106 Journal of Neurology, Neurosurgery, and Psychiatry 1990;53:106-113 J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.53.2.106 on 1 February 1990. Downloaded from Syringomyelia and arachnoiditis

L R Caplan, A B Norohna, LL Amico

Abstract and weakness in his right hand. Months later, Five patients with chronic arachnoiditis he developed sensory loss and weakness of the and syringomyelia were studied. Three hands, more noticeable in the left than the patients had early life meningitis and right. Atrophy, frequent burns, and hand developed symptoms of syringomyelia tremor were reported by the patient. Four eight, 21, and 23 years after the acute years later, the lower extremities became weak, infection. One patient had a spinal dural initially on the right side. He then experienced thoracic AVM and developed a thoracic weakness in the left leg which soon became syrinx 11 years after spinal subarachnoid more severe than in the right. He complained of haemorrhage and five years after surgery a drawing, burning pain in both arms from the on the AVM. A fifth patient had tuber- hands to the radial forearms and from the hips culous meningitis with transient spinal to the toes. cord dysfunction followed by develop- In 1943 (aged 46), he was first evaluated at ment ofa lumbar syrinx seven years later. the Harvard Neurological Unit at Boston City Arachnoiditis can cause syrinx formation Hospital. There was diminished body hair and by obliterating the spinal vasculature burn scars on his fingers. Mental function and causing ischaemia. Small cystic regions cranial nerves were normal except for a slight of myelomalacia coalesce to form left lower facial droop and slighlt leftward cavities. In other patients, central cord protrusion of the tongue. Upper extremity ischaemia mimics syringomyelia but no muscles, especially the deltoids and intrinsic cavitation is present. Scar formation with hand muscles, were atrophied and occasional spinal block leads to altered dynamics of fasciculations were noted. There was bilateral cerebrospinal fluid (CSF) flow and con- lower extremity weakness with a left foot drop tributes to the formation of spinal cord and atrophy of the left tibialis anticus. An cystic cavities inconstant intermittent "piano playing" tremor was seen in the hands. Upper extremity reflexes were absent except for a weak right Symptomatic or secondary syringomyelia triceps jerk but lower extremity reflexes were refers to spinal cord cysts, often long and exaggerated with right ankle clonus and exten-

tubular, that are caused by other recognised sor plantar responses. Pin and thermal sensa- http://jnnp.bmj.com/ disease processes. Intramedullary spinal cord tion were lost in the hands, radial forearms and tumours are sometimes associated with a syrinx entire left leg. Touch was also decreased in usually because ofsecretion offluids by tumour these parts but to a lesser degree. Vibration cells or necrotic cavitation of the neoplasm. sense was lost at both wrists, the right elbow, Scarring of the spinal meninges (usually term- and the left leg below the knee. Position sense ed "arachnoiditis" though both the pia mater was diminished below T3. Gait was unsteady and arachnoid are involved), has also been and wide-based and was characterised by over- reported as a cause of secondary syringomyelia. steppage due to a left foot drop. Lumbar on September 24, 2021 by guest. Protected copyright. The arachnoiditis may be caused by trauma,''12 puncture revealed normal fluid and dynamics. pyogenic infection,'3 14 tuberculous menin- He was placed in a chronic care unit, at the gitis,'"20 luetic meningitis,2"52' bleeding into Long Island Hospital, where he was examined the meninges'822 and post operative scarring.'3 by successive generations of Harvard Medical Department of Neurology, Michael Though arachnoiditis is known to be associated School students, residents and attending Reese Hospital with syrinx formation, the mechanism ofsyrin- physicians and considered to be an example of L R Caplan gomyelia is not well understood. We report five "classic syringomyelia". He became progres- L L Amico patients with non-traumatic arachnoiditis who sively quadriplegic and bedridden and was Department of later developed syringomyelia. Neurology, the readmitted to the Neurological Unit in 1966. University of Chicago At that time his mentation and cranial nerve Hospitals and Clinics functions were normal. There was diffuse mus- A B Norohna Case reports cle weakness; he could not lift his head from the Correspondence to: Case 1. This man was observed extensively extend his outstretched hands, sit up Dr Louis R Caplan, pillow, Department ofNeurology, during many years and studied at necropsy. In from a supine position, maintain wrist flexion New England Medical 1914 (aged 17), whilst in the army, he suffered or or move his hands. The right Center, 750 Washington extension, Street, Boston, MA, 02111, an acute infectious illness that was diagnosed lower extremity was completely immobile, but United States. by lumbar puncture as meningitis. He made a he could lift his left leg from the bed. The lower Received 28 February 1989 good recovery except for temporary strabismus and in revised form extremities were very spastic and sensory 23 August 1989. and continued to serve in the army until 1919. stimuli evoked flexor spasms in the left foot. Accepted 6 September 1989 In 1935 (aged 38), he noted loss of sensation. There were no upper extremity reflexes; knee Syringomyelia and arachnoiditis 107 J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.53.2.106 on 1 February 1990. Downloaded from and ankle reflexes were exaggerated and both was removed but there were no changes in the ankles showed sustained clonus. Both plantar neurological symptoms and signs in the post responses were extensor. Position and vibra- operative period. tion sense were impaired below C5. There was In 1981 (aged 47), she noticed increased complete sensory loss to all modalities below weakness of the left leg. Urinary retention TI on the left and a relative loss to pin prick developed and was treated with an indwelling below T6 on the right. All sensory modalities catheter. Her left hand became weak and the were lost in the C5, C6 and C7 dermatomes on inside of the hand was numb. The left half of the right. CSF protein was 260 mg per cent, the face also became numb and she experienced later 185 mg per cent. CSF dynamics were occasional vertigo. Examination revealed abnormal and myelography confirmed an ir- rotatory nystagmus greater on left gaze. The regular high cervical block. He died of pupils were small but reacted to light. Pin and pneumonia after a brief stay in another ex- thermal sensations were diminished on the left tended care unit. face while touch perception was normal. The At necropsy, all layers of the meninges were left corneal reflex was diminished. There was severely scarred and adherent to each other. wasting and weakness of the left intrinsic hand The thickened dura mater was densely ad- muscles and some weakness of the right wrist herent to the underlying bony skeleton, making extensors and intrinsic hand muscles. The it difficult to extract the spinal cord intact. The lower extremities were quite weak and spastic. meninges of the posterior fossa were also Deep tendon reflexes were exaggerated except scarred. There was no cavitation or slit within for the left biceps and brachioradial jerks which the medulla. The spinal cord was thin, atro- were absent. There was bilateral ankle clonus phic, and flattened, especially in the cervical and plantar responses were extensor. Vibra- and thoracic regions, but extending through tion, position, pain and temperature sensation lubar segments. Microscopic sections con- were diminished below T7 bilaterally. There firmed severe fibrosis and thickening of the was decreased pin and thermal sensation in the meninges. Both arteries and veins showed left arm, face and neck. Cranial CT was nor- fibrous degeneration of vessel walls. At times, mal. Myelography using metrizamide that we in the areas of necrosis, there was extensive introduced through a lateral Cl-C2 puncture connective tissue proliferation with accumula- revealed a nearly total block at T5 with some tion of dense eosinophilic staining collagen dye descending to T6-7. The cord was widened surrounding thickened vessels. There were few at T6 and in the cervical region. CT of the remaining inflammatory cells and no granu- dorsal spine during metrizamide myelography lomas. showed a cystic swelling within the cord. The cervical cord was reduced to a thin Somatosensory evoked responses could not be ribbon with extensive central necrosis and obtained with stimulation of the left peroneal, cavity formation. The cavity was collapsed, saphenous, or median nerves. Denervation was smooth and often bilobed, but there were no present in the left C8 and TI root innervated lining cells nor a well formed wall. There were muscles. Blink response recording was abnor- few remaining anterior horn cells in the cervical mal in the left supraorbital region. The electro- or upper thoracic cord. The cervical roots were physiological abnormalities were consistent

thin. The dorsal and ventral roots also showed with a lesion affecting the left cervical spinal http://jnnp.bmj.com/ moderate to marked loss of myelin. There was cord and lower medulla. Spinal angiography some Schwann cell proliferation. was normal. The thoracic cord was also flattened. The At surgical exploration, there were dense central zones stained poorly for myelin and had dural and arachnoid adhesions at T6, but no occasional small cavities. Caps of peripheral residual AVM. The spinal cord was dilated myelin remained. The corticospinal tracts were above the cicatrix. Incision of the dilated cord decimated throughout the thoracic and lumbar led to fluid drainage from a syrinx and a cord. The spinocerebellar tracts and posterior catheter was placed within the cavity. Micros- on September 24, 2021 by guest. Protected copyright. columns were scarred especially at the C7 and copic examination of material removed at the TI region as part of the general destruction. T6 level revealed only dense fibrocollagenous The lumbar roots were also thin and enmeshed tissue. Postoperatively, her legs were slightly within adhesive arachnoidal scarring which weaker. extended to the filum terminale and cauda Two years later, she noticed increasing equina. weakness in both hands. The left pupil was Case 2 In 1970, aged 36, this woman suddenly miotic and left nystagmus and left facial hypal- felt unwell and by the end of the day had gesia were unchanged. The left intrinsic hand difficulty in walking, especially with her right muscles were weak and atrophic. She was leg. She was admitted to hospital. The spinal confined to a wheelchair. fluid was bloody. She did not recall the initial Case 3 In 1975, aged 40, this patient developed two weeks in hospital, and remembered no fever, myalgia and lethargy, complaints which pain, headache, or backache. After recovery, persisted for five weeks before she was admit- her right foot remained numb. In 1976, she ted to hospital with a stiff neck and stupor. noticed increased numbness in her right leg, Lumbar puncture contained 3,024 WBC/mm3 dragging of both feet especially the right foot all lymphocytes. Protein was 90 mg/dL, glu- and urinary hesitancy. There were no acute cose 23 mg/dL. After isoniazid, ethambutol attacks or pain. Neurosurgical exploration and corticosteroids, she improved but com- showed a dural arteriovenous malformation plained of occasional paresthesiae below the centred around the T6 level. The malformation mid thoracic level particularly on the left. She 108 Caplan, Norohna, Amico J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.53.2.106 on 1 February 1990. Downloaded from Figure 1 Myelography of the lower thoracic spinal cord (fig 1). CT of (Case 3). Widened lower the dorsal region after metrizamide revealed thoracic cord. contrast material within the cord from T8 to TI11 (fig 2). The cord was widened from T7 to LI. MRI axial sections from a first generation scanner showed a large fluid compartment within the lower thoracic cord surrounded by a thin rim of spinal tissue. During the ensuing weeks, she began to notice slight tingling and prickling in her left arm and an unusual feeling around her lips and nose. There was pain in the left shoulder. Exploration confirmed severe arachnoiditis in the region ofthe conus medullaris. Rostral to the scarring was a fluid filled cavity into which a silastic tube was placed and drained into the peritoneum. Postoperatively, her walking im- proved, but she had more difficulty initiating urination. The left lower extremity below LI was more "numb" but the facial and arm paresthesiae were gone. Case 4 This was a 26 year old woman, who noticed a right foot drop in 1979 followed by weakness of the right arm. There was no pain and she had no sensory complaints. The right sided weakness remained unchanged until 1981, but increased after the birth ofher second child after which weakness progressed to involve the left hand. She had been admitted to hospital for meningitis at the age ofone year. At that time, a gram stain of CSF showed diplococci, and penicillin was given. Examination in August, 1983 revealed a woman ofbelow average intelligence. Horizon- tal and vertical nystagmus were present and both corneal reflexes were diminished. There was slight right facial weakness and decreased hearing in the left ear. Both hands showed atrophy of intrinsic muscles. Both arms were had urinary retention which required cathetter- severely weakened and the lower extremities isation. There was moderate weakness of both were moderately weak. Biceps and bra-

legs with bilateral partial foot drop, exag- chioradial reflexes were absent. Lower http://jnnp.bmj.com/ gerated reflexes and bilateral extensor planitar extremity reflexes were exaggerated more on responses. Hypalgesia was present below'T9. the left. The right plantar response was exten- All CSF cultures were normal, but she gavre a sor, the left equivocal. Hypalgesia was present history of tuberculosis at the age of seven. in both arms and in a mantle-type distribution She made an excellent recovery and returraed from C6 to T2. Position sense was impaired in to work, but later recalled slight numbnless both hands but was intact in the legs. CSF below the waist as a residue of her meningiitis. showed 4 WBC/mm3 and normal chemistry. In 1982, she developed difficulty in walking Skull and cervical spine films were normal with on September 24, 2021 by guest. Protected copyright.

and ...... more numbness in her toes. Pain develoiped . .. in her left chest and the left side below the wEaist ....~~~~~~~~...... felt heavy as ifit were "bursting". Examination revealed atrophy of the calf and intrinlsic muscles on the left. The left psoas and haIm- string muscles were moderately weak and thiere was a severe left foot drop. The right lovver extremity muscles were slightly weak. The Ileft knee and ankle jerks were absent, but ri~ght lower extremity reflexes were exaggerat ed. Abdominal reflexes were absent. Spontanec)us flexor spasms were present bilaterally, but the toes were immobile on plantar stimulation. IPin and thermal sensation were diminished in the feet. Walking deteriorated considerably duriing the following couple of months. Chest radLio- graphs revealed bilateral apical scarrirng. Myelography showed a high grade block in 1the T4-T8 region with irregular filling of tthe Figure 2 CT with metrizamide (Case 3). Contrast subarachnoid space and an increased diameter within cyst in lower thoracic cord. Syringomyelia and arachnoiditis 109 J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.53.2.106 on 1 February 1990. Downloaded from no signs of basilar impression. Brain CT was Arachnoiditis and the history of its association normal. Myelography demonstrated menin- with syringomyelia geal irregularities and fusiform expansion of Extensive scarring of the spinal meninges the cord from C2 to T2. CT with metrizamide usually involves all layers of the meninges, documented a syrinx in the bulb and cervical including the pia mater and dura mater. Never- cord. theless, spinal meningeal scarring is tradition- Case S In 1946 a 58 year old man was treated for ally referred to as "arachnoiditis" especially meningitis at Cook County Hospital, but the when the scarring causes loculation and records of that admission could not be found. interrupts and distorts the flow of contrast In 1954, his back was burned before he realised media introduced during myelography. The his clothes were on fire. At that time, examina- meningeal spaces, the subdural and subarach- tion revealed muscular atrophy in both arms, noid compartments, usually communicate and weakness of the arms and the right leg, spas- inflammatory disorders usually affect each ticity of the lower limbs, absent arm reflexes space to some degree.23 Spinal arachnoiditis and equivocal plantar responses. Pain and may be quite focal, and was originally des- temperature sensibility were lost from C4 to cribed as "arachnoiditis adhesiva circums- T12 on the left and C4 to LI on the right. cripta spinalis" or generalised, "arachnoiditis Vibration sense was reduced in both hands and adhesiva diffusa spinalis". feet. Chest radiographs showed a calcified Vulpian (1861) and Charcot and Joffrey24 granuloma in the right apex. Myelography were probably the first to describe cervical showed widening of the cervical cord consis- spinal cord cavitation associated with arach- tent with syringomyelia. CSF was under noiditis found at necropsy. Schwarz25 commen- normal pressure and contained 5 WBC/mm3, ted on chronic arachnoidal scarring in a patient protein 22 mg/dL, glucose 77 mg/dL. The with syphilitic sclerotic and cystic meninges cervical and thoracic cord were irradiated. who had focal regions of softening and cavita- In 1958, weakness increased in the arms and tion within the spinal cord. Alajouanine et al26 legs. Position sense was now impaired in the in a presentation to the Paris Neurological fingers and there was increased lower extremity Society, described six patients with spinal spasticity with clonus and Babinski signs. His arachnoiditis especially affecting the posterior condition stabilised until 1979 when he was re- aspect of the meninges who also had syrin- examined because of ataxia and increased gomyelia. Mackay27 in a report on chronic weakness. Sensation was now decreased over spinal arachnoiditis reviewed the literature and the right face. Cranial CT showed dilatation of reported five of his own patients defining the both lateral ventricles and slight dilatation of clinical and pathological features of chronic the third ventricle. The fourth ventricle was adhesive arachnoiditis. At necropsy two of normal and there was no evidence of an Mackay's patients showed severe arachnoiditis Arnold-Chiari malformation. In 1981, the CT with intense thickening of vessel walls in the was unchanged and myelography revealed no meninges. Both patients had spinal cord soft- block and an atrophic appearing cervical cord. ening, but cavitation was present in only one patient. Mackay pointed out that "cavitation of the cord may occur as a result of chronic

arachnoiditis and future studies on "syrin- http://jnnp.bmj.com/ Discussion gomyelia" must take this into account". Our case material includes three patients with Barnett'3 analysed previous reports, added new early life meningitis that later developed symp- cases, and summarised the then current infor- tomatic syringomyelia and syringobulbia. mation about chronic arachnoiditis and its There was a long delay, eight, 21 and 23 years, association with syringomyelia. Three dif- between meningitis and spinal cord symptoms. ferent patterns of arachnoiditis have been Each had a progressive course. In two patients, associated with syringomyelia: focal or diffuse CT documented a cervical cord cavity. In the scarring of the basal posterior fossa meninges, on September 24, 2021 by guest. Protected copyright. third, necropsy revealed severe arachnoidal diffuse adhesive spinal arachnoiditis and focal scarring with necrosis of the central portion of spinal meningeal cicatrix formation.2"30 Focal the spinal cord and cavity formation. All three scarring and opacification ofthe ventral surface of these patients had bulbar symptoms and of the brainstem has been associated with focal signs. A fourth patient, Case 3, developed focal cystic lesions in the midbrain, communicating thoracic cord symptoms and signs with a sen- with the cerebral aquaduct, the "keyhole sory level during the acute phase of presumed aqueduct syndrome" a special form of syrin- tuberculous meningitis. Seven years later, she gomyelia.3' had progressive dysfunction of the spinal cord, and CT, MRI, and surgery documented a Basal arachnoiditis cavity within the thoracic and lumbar spinal Scarring of the basal meninges in the posterior cord. A fifth patient, Case 2, developed cervical fossa is a recognised precursor of syringo- syringomyelia and likely syringobulbia after myelia, but we had no examples of this con- spinal subarachnoid haemorrhage and surgical dition in our data. Newman et al"8 proposed obliteration of a thoracic spinal AVM. In all that birth trauma, unusually frequent in the patients, spinal cavities developed after menin- history of patients who later develop syrin- geal scarring; in three patients, the meningeal gomyelia, is important in causing posterior scarring was diffuse and in two quite focal. fossa arachnoid scarring in both normal None of the patients had evidence of Chiari- infants and those with Chiari malfor- type malformation or basilar impression. mations. McLaurin et al" produced cervical 110 Caplan, Norohna, Amico J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.53.2.106 on 1 February 1990. Downloaded from spinal cord cavitation experimentally in dogs traumatic intraspinal haematoma could by injecting kaolin into the cisterna magna. As develop at the time of the injury and later with other posterior fossa and foramen mag- become hydrolysed leaving a slit-like cavity. num anomalies and lesions, intracranial pres- Alternately, the cord could be torn or sheared sure may be transmitted to the cerebral spinal during the injury, leaving a myelomalacic cord. cord causing a "communicating syringo- This softened area would be in continuity with myelia".33 Gardner34 proposed that CSF the subarachnoid space immediately after travelled down into the dilated central spinal trauma. Gliosis develops at the edge ofthe tears canal from the floor of the fourth ventricle. so that the slit-like cavities are lined by glial Blockage of free flow of CSF within the suba- scars. Mechanical factors might force spinal rachnoid space at or above the foramen mag- fluid up or down the cavities thus expanding num must somehow facilitate syrinx formation. them.'034 Once the cavity has begun to form, subsequent cranial-spinal pressure differ- Trauma with delayed syringomyelia ences,34 "sloshing" of fluid33 or mechanical Focal scarring of the meninges has been known forces related to respiration, movement, or to cause syrinx formation especially in patients straining7 could cause gradual enlargement of who have had spinal trauma. Gordon Holmes' the cavities. These hypotheses do not explain in his Goulstonian lectures on spinal cord the sometimes long delay in symptoms; gradual injuries commented on "curious cavities, enlargement ofan intramedullary lesion caused roughly cylindrical .. . in the segment of the by an intraspinal slit or haematoma should be spinal cord adjoining the lesion either in those associated with severe paraplegia directly after above it or below or both." These often ex- injury, and progression should begin soon tended a considerable distance, in some cases after. Alternatively, the mechanism of late four or five segments and at the ends furthest syrinx formation could involve the meningeal from the wound they were occasionally the only cicatrix not just the intraspinal lesions. Menin- indication of any abnormality. Some cavities geal fibrosis and scarring with adhesions takes were found above and below the lesion while time to develop. others occurred just below it. Barnett et al ' Trauma is an excellent example of focal studied 591 patients with traumatic paraplegia meningeal scarring (meningitis circumscripta). seen during an 18 year period and identified Two of our patients developed syringomyelia eight who later developed spinal cord symp- after focal non-traumatic scarring. One patient toms rostral to their original traumatic lesion. had a spinal AVM that bled and was repaired Four of these eight patients had myelographic surgically. Later exploration confirmed a confirmation of cervical spinal cord enlarge- severe focal adhesive meningeal scar. The ment. Upper extremity paresthesiae, numb- second patient had tuberculous meningitis ness, weakness, or reflex loss and sometimes with focal signs in the thoracic cord which facial numbness developed one to 14 years after cleared rapidly. The patient with focal bleeding the original trauma (average five to six years). developed worsening of function in spinal Progressive late post-traumatic syringomyelia segments above and below her AVM scar five was identified in six of 659 patients (0 9 per years after surgery, and the patient with tuber- cent) admitted to a referral centre for spinal culous meningitis deteriorated seven years

cord injuries.4 Syringomyelia was diagnosed after her acute infection and a syrinx developed http://jnnp.bmj.com/ five to 23 years (average 13 years) after the below her prior lesion. Both patients had cord original traumatic injury. Shannon et al5 injury as well as meningeal inflammation. They reported 13 patients with post-traumatic syrin- are thus comparable to patients with trauma gomyelia. Incomplete spinal cord lesions were and incomplete paraplegia. as commonly complicated by late syrinx forma- tion as were patients with complete spinal cord transections. In patients with post-traumatic syringo- Non-traumatic spinal arachnoiditis and on September 24, 2021 by guest. Protected copyright. myelia, the initial symptom referable to the syringomyelia syrinx is usually pain, especially precipitated Barnett'3 reviewed seven well documented by coughing, sneezing, or otherwise straining; previous examples of syringomyelia due to paresthesiae, numbness, and unwitting hand non-traumatic spinal arachnoiditis and added injuries and burns follow and paresis and five new cases. Among these twelve cases atrophy develop much later.9 Sensory symp- antecedents were: subarachnoid haemorrhage,2 toms can involve the face as well as the upper pyogenic meningitis,2 Pott's disease,' spinal limbs. When syringo-peritoneal shunting of anaesthetic,' spinal surgery,2 and unknown.4 In CSF has been helpful, the relief of pain has some patients, spinal cord dysfunction was been the first and most frequent symptom to recognised at the time of the injury or illness, show improvement.2035 At surgery or necropsy but in other patients symptoms were delayed in patients with a previous trauma, there is for as long as 13 to 17 years (average delay 4.6 usually scarring of the meninges with cicatrix years). The cavities in the patients in Barnett's formation at the site of maximum injury as well series'3 always involved the spinal cord maxi- as a syrinx. Occasionally, a large accumulation mally in the segments beneath the thickened of fluid forms within the meninges as an meninges and always affected the thoracic arachnoid cyst that compresses the spinal cord cord. In nine patients, there was severe local- externally. '3 ised arachnoidal scarring and three patients Theories abound as to why the syringo- had cystic fluid collections within the scarred myelia cysts form and why they expand. A arachnoid. Syringomyelia and arachnoiditis ill J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.53.2.106 on 1 February 1990. Downloaded from Tuberculous meningitis patients referred to their centre in Addis Ababa Tuberculous meningitis is often complicated with clinical findings indicative of arach- by transverse myelitis and polyradiculitis and noiditis. Among 200 selected cases studied, 90 can cause chronic meningeal scarring, ad- per cent had dissociated sensory loss, a hesions and spinal block.'6 Marinesco2' des-. "syringomyelia syndrome," and 95 of 105 cribed a patient with chronic "hypertrophic" patients that had myelography had radio- meningitis and spinal cord cavities who died of graphically confirmed adhesive arachnoiditis. pulmonary tuberculosis. Savoiardo"7 reported Some patients with diffuse meningeal inflam- a patient with tuberculous meningitis who was mation also have focal regions of more severe treated with intrathecal streptomycin and ison- scarring which may be associated with focal iazid. Slight paraparesis accompanied the spinal myelographic block. We have reported original infection and, during a relapse the three patients (cases 1, 4, and 5) with presumed following year, the patient became severely pyogenic meningitis. All had meningitis in paraplegic. An arachnoidal scar and complete youth and no details were available concerning spinal block were demonstrated. After a stable the signs and symptoms that accompanied the period of 12 years, he developed arm paresth- acute infection. One had presumed esiae, weakness, and numbness. Air myelogra- pneumococcal infection but no pathogen was phy confirmed a pocket of arachnoiditis with a identified in the other two patients. Patient block at T1O and an air-filled cavity extending one, at necropsy, had a diffuse adhesive menin- rostrally to C1. Feigen et al 8 described a gitis, worse in some regions. In these three patient with Pott's disease with severe kyphos- patients symptoms related to syringomyelia coliosis who had a segment of spinal cord were delayed an average of 17 years. removed that showed a syringomyelic cavity. Barnett" also described a patient with Pott's Subarachnoid or spinal bleeding and disease who became paraplegic at the age of 15 syringomyelia in association with tuberculous osteomyelitis of We could find only two previous reports of T2, T3 and T4. She recovered but later syringomyelia following spinal subarachnoid developed a syringomyelic cavity and arach- bleeding. A 37 year old woman with systemic noidal adhesions were identified at surgery. lupus erythematosus developed a "thoracic Barnett has reviewed the literature on Pott's transverse myelitis" with associated subarach- disease and syringomyelia; most case reports noid and subdural haemorrhage.'8 This patient were before 1920.'5 Paraplegia in patients with remained paraplegic until her death from active Pott's disease has been found in patients with- lupus. At necropsy, the dura over the low.er out spinal obstruction and is usually attributed thoracic spinal cord was firmly adherent to the to an arteritis and cord ischaemia. Gimenez- leptomeninges and spinal cord and there was a Roldan et al '9 added four new cases of tuber- large cavity at this and lower spinal levels. culous meningitis and delayed syrinx forma- Blood pigment was found within the meningeal tion. One patient had syringobulbia, syringo- scar tissue. Nelson22 described a man with myelia and hydrocephalus following severe chronic thrombocytopenic purpura and a con- early life tuberculous meningitis with scarring firmed subarachnoid haemorrhage who de- in the posterior fossa. The other three patients veloped a paraparesis and spinal block during a

all developed tuberculous meningitis in their period of four years. Necropsy showed exten- http://jnnp.bmj.com/ second or third decades (ages 10, 18 and 26 sive thickening of the dura mater and pia- years) and all received intrathecal strepto- arachnoid and extensive cavitation of the mycin. None had recognised spinal cord symp- thoracic and lumbar segments of the spinal toms or signs during the acute infection. Signs cord. Our patient with a spinal AVM had an of spinal cord dysfunction began four, six, and episode of subarachnoid haemorrhage but also eight years later and progressed rapidly and had spinal surgery to remove the AVM. Symp- inexorably thereafter. All had complete spinal toms of syringomyelia developed five years block in the thoracic region with fragmentation after her surgery and 11 years after the subara- on September 24, 2021 by guest. Protected copyright. of dye in other regions; all had cavities above chnoid haemorrhage. the level of the block. Our single patient (Case 3) with tuberculous meningitis had symptoms Conclusions and mechanisms of syrinxformation at the time of meningitis that cleared but later We believe that analysis of our case material developed a syrinx below the level of the and previous cases of arachnoiditis (traumatic previous symptoms. and non-traumatic) favours two predominant mechanisms of syrinx formation. Diffuse meningitis and syringomyelia 1. Vascular. The inflammatory disorder in the Pyogenic meningitis probably causes diffuse meninges leads to severe scarring of the menin- spinal and cranial meningeal inflanmmation. ges and the vessels that travel within the Syringomyelia has been described after pyo- meninges. Barnett315 and Mackay27 both des- genic infection but most often the offending cribed the presence of severe vascular changes organism has not been identified.'3 14 27 The and patient 1 showed extensive obliteration of diagnosis ofpyogenicinfection is made because spinal cord feeding arteries. These extensive of the extensive pleocytosis which argues vascular changes lead to cord ischaemia. The against a viral meningitis. Diffuse adhesive most severely involved segments are those arachnoiditis is probably more common in supplied by the anterior spinal arteries which underdeveloped countries and is caused by a derive from radicular arteries each 4 or 5 mixture of pyogenic, tuberculous, fungal and segments, and in the arterial boundary zones parasitic infections. Jenik et al '4 identified 507 between the anterior and posterior spinal 12 Caplan, Norohna, Amico J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.53.2.106 on 1 February 1990. Downloaded from Figure 3 Diagram of The long duration of latency between the arterial supply of cord. initial trauma, inflammatory event, or bleeding Border zone in the centre and the frequent absence of important spinal zone of the cord is depicted in broken lines. cord symptoms and signs at the time of the illness support the argument for the import- ance of the meningeal process rather than a primary intramedullary aetiology of the syrin- xes. In fact, most patients had no neurological symptoms and signs in the interval between the initial injury or illness and the development of the syrinx. The initiating event sets off the process of scarring outside the spinal cord in the spinal meninges. Ultimately, the meningeal scarring becomes severe and adhesive leading to complete or nearly complete spinal myelo- a graphic block. This period of development of adhesive changes can be months, but more often is years. The spinal block interferes with arteries (fig 3). This area includes the central CSF circulation and causes spinal cord cord and the crossing spinothalmic fibres, and ischaemia, leading to cavitation or multiple the anterior horns and corticospinal tracts. areas ofmyelomalacia. The advent ofMRI and Ischaemia gives rise to areas of softening and metrizamide myelography with CT may help cavity formation. This can occur focally in the to clarify the mechanism of this process in the case of focal meningeal scarring or multifocally future.39 when the meningeal scarring is more diffuse. MacDonald et al'2 reported two patients whose findings supported a vascular mechan- 1 Holmes G. The Goulstonian lectures on Spinal Injuries of ism of damage associated with arachnoiditis. Warfare. Br Med J 1915;2:769-74. 2 Schiep G. Syringomyelia and syringobulbia. In: Vinken G, Both patients had severe spinal trauma and Bruyn G, eds. Handbook of clinical neurology Vol developed delayed symptoms and radiological 32, Congenital malformations of the spinal cord. Amsterdam: North Holland Publishing Co, Amsterdam, findings suggesting delayed syrinx formation. 1978:255-327. At surgery, each had arachnoidal scarring and 3 Barnett H, Botterell E, Jousse A, Wynn-Jones M. Progres- sive myelopathy as a sequel to traumatic paraplegia. Brain the spinal cord contained multiple small 1966;89:159-73. microcysts less than 1 mm in diameter that 4 Rossier A, Foo D, Shillito J, Naheedy M, Sweet W, Dyro F, Sarkarati M. Progressive late post-traumatic syringo- undoubtedly represented an ischaemic myelia. Paraplegia 1981;19:96-7. myelomalacia but cysts had not yet coalesced to 5 Shannon N, Symon L, Logue V, Cull D, King J, Kendall B. Clinical features, investigation, and treatment of post- form true syringomyelic cavities. traumatic syringomyelia. J Neurol Neurosurg Psychiatry A syringomyelic syndrome could occur when 1981;44:35-42. 6 Oakley J, Ojemann G, Alvord E. Post-traumatic syringo- the central spinal structures are ischaemic even myelia. J Neurosurg 1981;55:276-81. when true cavities do not form. In that case, 7 McLean D, Miller J, Allen P, Ezzeddin S. Post-traumatic syringomyelia. J Neurosurg 1973;39:485-92. ischaemia would mimic syringomyelia. In 8 Klawans H. Delayed traumatic syringomyelia. Dis Nervous

other cases, microcysts probably form in areas System 1968;29:525-8. http://jnnp.bmj.com/ 9 Martin C, Maury M. Syndrome Syringomyelique apres of spinal cord softening and coalesce to form paraplegia traumatique. La Presse Medicale 1964;72: true cavities. Our patient 1 with necropsy data 2839-42. 10 Nurick S, Russel A, Deck M. Cystic degeneration of the is an excellent example of arachnoiditis, caus- spinal cord following spinal cord injury. Brain 1970; ing ischaemic myelomalacia and secondary 93:211-22. 11 Abraham J, Paterson A, Bothra M, Mofti A, Taylor GW. cavitation. Omentomyelo-synangiosis in the management of chronic traumatic paraplegia: case report. Paraplegia 1987;25: 44-9. 2. Focal scarring with spinal block. Spinal block 12 MacDonald RL, Findlay JM, Tator CH. spinal

Microcystic on September 24, 2021 by guest. Protected copyright. interferes with the circulation of CSF. Altered cord degeneration causing post-traumatic myelopathy. J Neurosurg 1988;68:466-71. mechanics and pressure could force CSF into 13 Barnett H. Sryingomyelia associated with spinal arach- the central canal and cause expansion of that noiditis. In: Barnett H, Foster J, Hudgson P. Syringo- myelia. London: Saunders, 1973:220-44. structure.35 Alternatively, expansion of the 14 Jenik F, Tekle-Haimanot R, Hamory B. Non-traumatic central canal or cord cavity could extend into adhesive arachnoiditis as a cause ofspinal cord syndromes. Investigations of507 patients. Paraplegia 1981;19:140-54. areas of damage for example, during trauma or 15 Barnett H. The pathogenesis of syringomyelic cavitation infection. The following case supports this associated with arachnoiditis localized to the spinal canal. In: Barnett H, Foster J, Hudgson P, eds. Syringomyelia. explanation."6 A 73 year old woman developed London: Saunders, 1973:245-60. back pain and a large syringomyelic cavity was 16 Brooks W, Fletcher A, Wilson R. Spinal cord complications of Tuberculous meningitis. Quarterly J of Medicine 1954; discovered in the conus medullaris at surgery. 23:275-90. Above the lesion was a calcified meningioma at 17 Savoiardo M. Syringomyelia associated with postmeningitic spinal arachnoiditis. Neurology 1976;26:551-4. T9 which had compressed the spinal cord 18 Feigin I, Ogata V, Budzelovich G. Syringomyelia: the role of altering drainage below. Examples of posterior edema in its pathogenesis. JNeuropath Exper Neurol 1971; 30:216-32. fossa brain tumours with subsequent spinal 19 Gimenez-Roldan S, Esteban A, Benito C. Communicating syrinxes have also been reported.7 38 The syringomyelia following cured tuberculous meningitis. J Neurolog Sci 1974;23:185-97. mechanism of syringomyelia with Arnold- 20 Suzuki M, Davis C, Symon L, Gentili F. Syringoperitoneal Chiari malformations and posterior fossa ara- shunt for treatment ofcord cavitation. J Neurol Neurosurg Psychiatry 1985;48:620-7. chnoiditis are abnormal spinal fluid circulation 21 Marinesco G. Contribution a l'etude de la pachymeningite and drainage. Some cerebrospinal intra- hypertrophique. Revue Neurologique 1916;30(10):233-53. 22 Nelson J. Intramedullary cavitation resulting from adhesive medullary tumours might also produce cavita- spinal arachnoiditis. Arch Neurol Psychiatry 1943;50:1-7. tion by causing a spinal block. 23 Nelson D. Dangers from methylpredisolone acetate therapy Syringomyelia and arachnoiditis 113 J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.53.2.106 on 1 February 1990. Downloaded from by intraspinal injection. Arch Neurol 1988;45:804-6. Keyhole aquaduct syndrome. Arch Neurol 1986;43:926-9. 24 Charcot J, Joffroy A. Deux cas d'atrophic musculaire 32 McLaurin R, Bailey 0, Schurr 0, Ingraham F. Myelo- progressive avec lesions de la substance grise et des malacia and multiple cavitation ofspinal cord secondary to fasiceaux anterolateraux de la moeille 'epinie're. Arch adhesive arachnoiditis: An experimental study. Arch Physiol 1869;2:354-63. Pathol 1954;57:138-46. 25 Schwarz E. Praparate von einem falle syphilitischer 33 Williams B. On the pathogenesis ofsyringomyelia: A review. myelomeningitis mit holenbildung im Ruchenmarke und J Roy Soc Med 1980,73:798-806. besonderen degenerativen Veranderungen der 34 Gardner WJ. 7he dysraphic states. Amsterdam: Excerpta Neurologlia. Wien Klin Wchschr 1897;10:177. Medica, 1973. 26 Alajouanine T, Hornet T, TI hurel R, Andre R. Le feutrage 35 Barbaro N, Wilson C, Gutin P, Edwards M. Surgical arachnoidien posterieur dans la syringomelie. Rev, treatment of syringomyelia: favorable results with Neurologique 1935;64:91-8. syringoperitoneal shunting. J Neurosurg 1984;61:531-8. 27 Mackay R. Chronic adhesive spinal arachnoiditis. JAMA 36 Blaylock R. Hydrosyringomvelia of the conus medullaris 1939;1 12:802-8. associated with a thoracic meningioma. J Neurosurg 1981; 28 Newman P, TIerenty T, Foster J. Some observations on the 54:833-5. pathogenesis of syringomvelia. J Neurol Neurosurg 37 Harbitz F, Lossius E. Extra-medullary tumor: Arachnoiditis Psychiatry 1981;44:964-9. fibrosa cystica et ossificans; Gliosis of the medulla. Acta 29 Hankinson J. Syringomyelia and the surgeon. In: Williams Psychiatr et Neurol 1929;4:51-64. D, ed. Modern Trends in Neurology. London: Butter- 38 Tauber E, Langworthy 0. A Study of Syringomyelia and worths, 1970:127-48. formation of cavities in the Spinal Cord. J Nerv Ment Dis 30 Appleby A, Bradley W, Foster J, Hankinson V, Hudgson P. 1935;81 :245-64. Syringomyelia due to chronic arachnoiditis at the foramen 39 Simmons JD, Norman D, Newton TH. Pre-operative magnum. J Neurol Sci 1969;8:451-64. demonstration of post-inflammatory syringomyelia. 31 De la Monte S, Horowitz S, Larocque A, Richardson EP. AJNR 1983;4:625-8.

Robert Graves and multiple neuritis progressive pace, extended over the whole of both Many studies of paralysis of the limbs had been extremities. Persons lay in bed powerless and help- conducted in the 18th and 19th centuries, but the less, and continued in this state for weeks and even concept that this might result from diseases remote from months ... the brain, cord and spinal roots was not recognised. At last, at some period of the disease, motion and Wasting was due to disorders ofthe muscles and sensory sensation gradually returned, and a recovery gen- loss related to defects of the skin. It was recognised that erally took place, although, in some instances, the these symptoms occurred in "alcoholic paraplegia" and paralysis was very capricious, vanishing and again probably in lead and arsenic poisoning where they were reappearing. caused by the diarrhoea or constipation. Samuel Wilks The French pathologists, you may be sure, sear- had thought the cause might be due to a reflex paralysis ched anxiously in the nervous centres for the cause of "the cord is in no way structurally altered, and therefore this strange disorder, and could find none; there was no evident lesion, functional or organic, discoverable may ... recover . . ."' Polyneuropathy is a recent name replacing Ernst von in the brain, cerebellum or spinal marrow . . Can Leyden's (1832-1910) term2 "multiple neuritis". The anyone ... hesitate to believe that paralysis ... may account was one of beriberi neuritis arise from disease commencing and originating in

first probably http://jnnp.bmj.com/ described by Bontius in 1642.' Robert Graves (1796- the nervous extremities alone?" 1853) in 1843 deserves credit for first predicating Gowers gave him less than credit due, but Trousseau disease of the peripheral nerves as a cause of paralysis. remarked that "Graves had created a class of peripheral Graves, remembered for his description of exophthal- or reflex paralyses ." Octave Landry's celebrated mic goitre (after Caleb Parry), was a Dublin graduate report of ascending paralysis6 in a 43 year old paver who had travelled with the artist Turner in Europe. In followed in 1859 but, curiously, the peripheral nerves Paris in 1828 he observed the remarkable and obscure, were not examined. epidemic of acute sensori-motor polyneuropathy. Des- It was left to Louis Dumenil (1823-90) to demon-

cribed by Auguste-Francois Chomel4 it was known as strate in a 71 year old stone cutter afflicted by a Landry's on September 24, 2021 by guest. Protected copyright. epidemie de Paris. Graves's account in 1843 is to be paralysis the pathological evidence of "a genuine atrophy found in his Clinical Lectures': of the medullary substance of the peripheral nerve "One of the most remarkable examples of disease of tubes" and related loss of transverse striations of the nervous system commencing in the extremities, shrunken muscle fibres in the periphery.7 and having no connection with lesions ofthe brain or JMS PEARCE spinal marrow, was the curious epi&mie de Paris, which occurred in the spring of 1828. Chomel has described this epidemic in the 9th number of the Journal Hebdomadaire, and having witnessed it myself in the months of July and August of the same year, I can bear testimony to the ability and accuracy 1 Wilks S. Lectures on diseases of the nervous system delivered at in of Guy's Hospital. London: Churchill, 1878. of his description. It began (frequently persons 2 Leyden, E von. Ueber poliomyelitis und neuritis. Z klin Med good constitution) with sensations of pricking and 1879-80;1:387-8. severe pain in the integuments of the hands and feet, 3 Bontius J. De medicina indorum (1642). English translation so acute a of sensibility, that 1769, chapter 1, libra IV. cited In: Ralph H Major, ed. accompanied by degree Classic descriptions of disease, 3rd edn. Oxford: Blackwell, the patients could not bear these parts to be touched 1945;605. by the bed-clothes. After some time, a few days, or 4 Chomel A-F. De l'epid&mie actuellement regnante a Paris. J even a few hours, a diminution, or even abolition of Hebomadaire de Medecin 1828;1:333. 5 Graves RJ. Clinical lectures on the practice of medicine. 2nd sensation took place in the affected members, they edn. London: New Sydenham Soc, 1884;574:579-80. became incapable of distinguishing the shape, tex- 6 Landry 0. Note sur la paralysie ascendante aigue. Gazette ture, or temperature of bodies, the power of motion Hebdomadaire de Medecin 1859;6:472-86. and were observed to become 7 Dumenil L. Paralysie peripherique du mouvement et du declined, finally they sentiment portant sur les quatre membres. Atrophie des altogether paralytic. The injury was not confined to rameaux nerveux des parties paralysees. Gazette Heb- the hands and feet alone, but, advancing with domadaire de Medecin. 1864;1:203.