63666ournal ofNeurology, Neurosurgery, and Psychiatry 1996;61:636-640 J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.61.6.636 on 1 December 1996. Downloaded from SHORT REPORT Massive nerve root enlargement in chronic inflammatory demyelinating polyneuropathy W Schady, P J Goulding, B R F Lecky, R H M King, C M L Smith Abstract series' and in up to a third of relapsing cases.4 Objective-To report three patients with Greatly enlarged nerve roots have been identi- chronic inflammatory demyelinating fied in a few typically affected patients at polyneuropathy (CIDP) presenting with necropsy,'6 by myelography,7 at surgery, and symptoms suggestive of cervical (one by MRI.9 "We report three patients who pre- patient) and lumbar root disease. sented with symptoms suggestive of radicu- Methods-Nerve conduction studies, lopathy, in whom MRI or CT myelography EMG, and nerve biopsy were carried out, showed massive nerve root hypertrophy. having found the nerve roots to be very Subsequent investigation, including nerve enlarged on MRI, CT myelography, and root biopsy in one patient, showed CIDP. at surgery. Results-Clinically, peripheral nerve thickening was slight or absent. Subsequently one patient developed facial Case reports nerve hypertrophy. This was mistaken for CASE 1 an inner ear tumour and biopsied, with A man aged 58 developed severe left groin consequent facial palsy. Neuro- pain while walking, eased by flexing the limb, physiological tests suggested a demyeli- with associated low backache and decreased nating polyneuropathy. Sural nerve walking speed. He then noticed deadness and biopsy showed in all cases some loss of increased sensitivity of his right little finger. myelinated fibres, inflammatory cell He was thought to have a cervical spondylotic infiltration, and a few onion bulbs. radiculomyelopathy, for which a decompres- Hypertrophic changes were much more sive cervical laminectomy was performed at prominent on posterior nerve root biopsy another hospital in 1985. The clinical and in one patient: many fibres were sur- radiological findings at that time are not rounded by several layers of Schwann cell known. The operation was not helpful and his cytoplasm. There was an excellent walking continued to deteriorate. By 1993 his http://jnnp.bmj.com/ response to steroids in two patients but condition had progressively worsened result- Department of not in the third (most advanced) patient, ing in weakness of his right arm and both legs, Neurology, who has benefited only marginally from sensory disturbance in his hands and in the Manchester Royal intravenous immunoglobulin therapy. lower half of his body, and occasional urge Infirmary, His balance was poor, especially Manchester, UK Conclusions-MRI of the cauda equina incontinence. W Schady may be a useful adjunct in the diagnosis of in the dark, and he was unable to stand with- P J Goulding CIDP. out the aid of a stick. There was no family his- on October 1, 2021 by guest. Protected copyright. Walton Centre for tory of polyneuropathy. Neurology and (3 Neurol Neurosurg Psychiatry 1996;61:636-640) Examination showed restricted neck and Neurosurgery, Rice Lane, Liverpool low back movements. There was profound L9 1AE, UK wasting of the forearms and small hand mus- B R F Lecky Keywords: root hypertrophy; chronic idiopathic cles, worse on the right. His upper limbs were Royal Free Hospital, demyelinating polyneuropathy very weak, more so distally, with moderate Pond Street, London predominantly proximal asymmetric weakness NW3 2QG, UK R H M King Chronic inflammatory demyelinating poly- of the lower limbs. All tendon reflexes were Royal Hallamshire neuropathy (CIDP) is a relapsing or chroni- absent but the plantar responses were exten- Hospital, Glossop cally progressive disorder most commonly sor. The peripheral nerves felt slightly thick- Road, Sheffield presenting with limb weakness, distal sensory ened. There was hypersensitivity of the skin in S10 2JF, UK 2 forearms and C M L Smith disturbance, and hyporeflexia.' The CSF both little fingers and medial Nerve con- loss from the umbilicus downwards in Correspondence to: protein is almost always raised.3 sensory Dr W Schady, Department duction studies show slowing of motor con- a patchy distribution. Joint position sense was of Neurology, Manchester in the feet and vibration could Royal Infirmary, Manchester duction and sural nerve biopsy discloses impaired only M13 9WL, UK. segmental demyelination and remyelina- be detected above the shoulders. He was Received 25 August 1995 tion.'I CIDP is one of the causes of "hyper- unable to stand without support but he could and in final revised form take a few with the aid of a stick. 7 August 1996 trophic neuropathy". Thickened peripheral steps Accepted 20 August 1996 nerves were detected in 11% of one large Romberg's test was strongly positive. Massive nerve root enlargement in chronic inflammatory demyelinating polyneuropathy 637 J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.61.6.636 on 1 December 1996. Downloaded from Figure 1 (a) MRI axial Tl weighted gradient echo image, patient 1; (b) myelogram, patient 2; (c) CT myelogram, patient 3. There is pronounced enlargement of the lumbosacral nerve roots, which in patient 1 (a) are seen to expand in a dumbbell shape outside the exit foramen (arrow). and slowing of nerve conduction and motor conduction block, in keeping with a demyeli- nating polyneuropathy. A lumbar laminectomy was undertaken to decompress the cauda equina. On opening the A blood count, erythrocyte sedimentation dura several thickened, white, and matted rate, liver and renal function tests, blood glu- nerve roots were seen (fig 2). No CSF was cose, immunoglobulins, and plasma protein obtained. A fascicular biopsy of a posterior and urine electrophoresis were all normal. A nerve root showed loss of myelinated axons full antibody screen (including MAG antibod- and a few endoneurial inflammatory cells. ies) was negative. Molecular genetic studies Many large fibres had thin myelin sheaths and http://jnnp.bmj.com/ disclosed no duplication at 17pl 1 2. No acid were surrounded by several layers of Schwann fast bacilli were seen on skin scrapings. cell cytoplasm ("onion bulbs"). A sural nerve Magnetic resonance imaging showed atrophy biopsy disclosed similar but less advanced of the cervical cord. There was striking bilat- changes. Unmyelinated axons were normal. eral enlargement of all cervical nerve roots The neurophysiological and pathological with widening of the exit foraminae, especially findings supported a diagnosis of CIDP. at C6-7 and C7-T1. The thoracic spine, cord, Treatment with prednisolone and azathio- and nerve roots appeared normal. There was prine resulted in initial worsening of hand on October 1, 2021 by guest. Protected copyright. homogeneously increased signal from the strength, bladder control, and mobility, such cauda equina, with multiple areas of nodular that he became unable to stand unassisted. enhancement and no visualisation of CSF. Pooled intravenous immunoglobulin therapy The lumbar nerve roots were grossly enlarged, (Sandoglobulin (04 g/kg/day) for five days filling and expanding the exit foramina (fig followed by monthly infusions of 22-24 g for la). Nerve conduction studies (table) showed 10 months) led to mild improvement in hand reduced sensory and motor action potentials function (less than 1 MRC grade) but had no Nerve conduction data Motor Sensory Amplitude (mVI) % Conduction block Distal latency (ms) Conzduction velocity (mls) Amlplitude (p V) Patient 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 Median 1.9 11-3 9-2 58 15 28 6-0 - 8 1 25 47 37 5 - 1 Ulnar 2 4 9-3 3-9 8 44 13 5-6 2 9 5 1 34 43 41 0 12 0 Peroneal 0 3 3-2 0 4 78 12 0 14-0 9 0 14 0 23 31 38 0* 1* 2* *Lower limb sensory action potentials are for the sural nerve. Compound muscle action potential amplitudes correspond to those obtained on distal nerve stimula- tion. Sensory action potentials were recorded orthodromically in the upper limbs and antidromically in the lower limbs. % Conduction block refers to the drop in motor potential amplitude between distal and proximal stimulation sites. 638 Schady, Goulding, Lecky, King, Smith 4: J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.61.6.636 on 1 December 1996. Downloaded from I Al" 1 P, ,-'..,i- Figure 2 Operativefindings in patient 1. The lumbar nerve roots are grossly thickened and matted together. sustained effect on lower limb strength. He has remained confined to a wheelchair. CASE 2 N. This 25 year old woman presented in 1989. AV. For several years she had noted minor non- .:, 's 1. .....1 specific leg weakness which she had attributed to being "unfit". In the previous year she had Figure 3 Sural nerve from patient 2 showing an onion developed progressive difficulty with climbing bulb consisting of a small, normally myelinatedfibre (A) stairs and had become unable to run or rise surrounded by two layers of circumferentially oriented from a squatting position. She had backache Schwann cells. The thinly myelinatedfibre (B) is surrounded by a less well defined layer ofsmall Schwann but no pain or sensory complaints. The upper cell profiles. Bar = 5 limbs were asymptomatic except for occa- gm. sional cramping of the hands. There was no family history of neuromuscular disease. Examination showed mild wasting and as well as small but definite deposits of both weakness of the small hand muscles. There CD4+ and CD8+ cells. was moderately severe symmetric wasting and The initial clinical impression was of a lum- weakness of the quadriceps and mild weakness bar polyradiculopathy, possibly in relation to of hip flexion, hip extension, and ankle dorsi- her spina bifida occulta. However, the results flexion. The upper limb reflexes were pre- of investigations pointed to CIDP and she was http://jnnp.bmj.com/ served but the knee jerks were sluggish and the therefore treated with 60 mg prednisolone and ankle jerks were absent.