Multiple Cranial Neuropathies
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Multiple Cranial Neuropathies Craig G. Carroll, D.O.,1 and William W. Campbell, M.D., M.S.H.A.2 ABSTRACT Patients presenting with multiple cranial neuropathies are not uncommon in neurologic clinical practice. The evaluation of these patients can often be overwhelming due to the vast and complicated etiologies as well as the potential for devastating neurologic outcomes. Dysfunction of the cranial nerves can occur anywhere in their course from intrinsic brainstem dysfunction to their peripheral courses. The focus of this review will be on the extramedullary causes of multiple cranial neuropathies as discussion of the brainstem syndromes is more relevant when considering intrinsic disorders of the brainstem. The goals are to provide the reader with an overview of those extramedullary conditions that have a predilection for causing multiple cranial nerve palsies. In turn, this will serve to provide a practical and systematic approach to allow for a more targeted diagnostic evaluation of this, often cumbersome, presentation. KEYWORDS: Multiple cranial neuropathy, cranial neuropathies, cranial nerve palsies, cranial nerve syndromes, cranial polyneuropathies Evaluating the patient with multiple cranial stem, and thus brainstem syndromes are often organized neuropathies presents a unique challenge for the diag- into eponymic syndromes. However, these classically nostician. The differential diagnosis is broad and in- described eponymic brainstem syndromes were reported cludes many life-threatening processes. Just as with any in an era where disorders such as tuberculomas, syphilitic other neurologic presentation, the first step in the gummas, and tumors were seen more often than today.1 evaluation requires correct localization. Processes affect- Many of these classically described brainstem syndromes ing multiple cranial nerves may involve intramedullary were not due to ischemia. In the current era, the vast structures of the brainstem as well as their extramedul- majority of brainstem syndromes are a result of vascular lary course. The focus of this review will be on the insults, mainly brainstem infarctions and hemorrhages, extramedullary disorders affecting multiple cranial often involving the lateral pons and medulla.2 Consid- nerves. ering the dominance of vascular etiologies of the brain- stem syndromes, a more practical classification of these syndromes is by the anatomical area or the major blood BRAINSTEM SYNDROMES vessel involved (Table 1). Examples of nonvascular This document was downloaded for personal use only. Unauthorized distribution is strictly prohibited. Prior to discussion of the extramedullary processes disorders that commonly affect the brainstem include causing dysfunction of multiple cranial nerves, a few demyelinating disease (multiple sclerosis [MS], acute points must be made about the brainstem syndromes. disseminated encephalomyelitis [ADEM]), intramedul- Many of the early neurologic pioneer clinicians described lary neoplasms (such as brainstem gliomas/ependymo- the findings due to a focal process affecting the brain- mas), brainstem encephalitis (Bickerstaff’s encephalitis), 1Department of Neurology, Naval Medical Center, Portsmouth, Disorders of the Cranial Nerves; Guest Editor, William W. Campbell, Virginia; 2Department of Neurology, Uniformed Services University M.D., M.S.H.A. of Health Sciences, Bethesda, Maryland. Semin Neurol 2009;29:53–65. Copyright # 2009 by Thieme Address for correspondence and reprint requests: Craig G. Carroll, Medical Publishers, Inc., 333 Seventh Avenue, New York, NY D.O., Head, Department of Neurology, Naval Medical Center Ports- 10001, USA. Tel: +1(212) 584-4662. mouth, 620 John Paul Jones Circle, Portsmouth, VA 23708 (e-mail: DOI 10.1055/s-0028-1124023. ISSN 0271-8235. [email protected]). 53 54 SEMINARS IN NEUROLOGY/VOLUME 29, NUMBER 1 2009 Table 1 Summary of the Brainstem Syndrome Organized by Anatomic Region and Blood Vessel Involved Syndrome Structures Involved Clinical Findings Comments Midbrain syndromes Corticospinal tract; corticobulbar Contralateral weakness of arm, Due to occlusion of the interpeduncular tract; cranial nerve III fibers; leg and face; ipsilateral cranial penetrating branches of the basilar red nucleus; superior cerebellar nerve III; contralateral tremor; or posterior cerebral artery or the peduncle contralateral ataxia posterior choroidal artery Medial inferior pontine Paramedian pontine reticular Ipsilateral CN VI or horizontal gaze Due to occlusion of paramedian formation; CN VI nucleus or palsy; ataxia. Paresis and perforating vessel fibers; middle cerebellar peduncle; impaired lemniscal sensation of corticospinal tract; medial contralateral limbs lemniscus Lateral inferior pontine Cranial nerve VII nucleus or fibers; Ipsilateral cerebellar ataxia; loss of Due to occlusion of anterior inferior (AICA syndrome) middle cerebellar peduncle; inferior pain and temperature sensation cerebellar artery cerebellar peduncle; corticospinal and diminished light touch sensation tract; principle and spinal nucleus of face; impaired taste sensation; of CN V; lateral spinothalamic tract; central Horner’s syndrome; solitary tract; flocculus and inferior deafness; peripheral type of facial surface of cerebellar hemisphere palsy. Loss of pain and temperature sensation of contralateral limbs Medial midpontine Middle cerebellar peduncle; Ipsilateral ataxia. Contralateral weakness Due to occlusion of paramedian corticospinal tract; medial of arm, leg, and face; gaze deviation; perforating vessel lemniscus Æ impaired lemniscal sensation Lateral midpontine Middle cerebellar peduncle; CN V Ipsilateral ataxia; weakness of muscles Due to occlusion of short motor and sensory nuclei or fibers of mastication; impaired facial circumferential artery sensation Medial superior Superior cerebellar peduncle and/or Ipsilateral ataxia; internuclear Due to occlusion of paramedian pontine middle cerebellar peduncle; medial ophthalmoplegia. Contralateral perforating vessel longitudinal fasciculus; central weakness of arm, leg, and face; tegmental tract; corticospinal Æ impaired lemniscal sensation. tract; medial lemniscus Palatal myoclonus Lateral superior pontine Superior cerebellar peduncle and Ipsilateral ataxia; Horner’s syndrome; Due to occlusion of superior (SCA syndrome, middle cerebellar peduncle; lateral skew deviation. Contralateral cerebellar or distal basilar artery Mills’ syndrome) spinothalamic tract; lateral part of impairment of pain, temperature, and medial lemniscus; superior lemniscal sensation. Vertigo; dysarthria; cerebellar hemisphere lateropulsion to side of lesion Medial medullary XII nucleus or fibers; medullary Ipsilateral tongue weakness; contralateral Due to ischemia in the distribution of syndrome pyramid(at/near decussation); hemiparesis (sparing the face); the paramedian perforator or the Æ medial lemniscus Æ impairment of posterior column anterior spinal artery, findings may function; lateral spinothalamic be bilateral and of variable laterality functions spared due to involvement of the pyramidal decussation and variations in the anatomy of the anterior spinal artery Lateral medullary Spinal tract of CN V and its nucleus; Loss of pain and temperature ipsilateral Due to ischemia in posterior inferior syndrome nucleus ambiguous; emerging fibers face and contralateral body; decreased cerebellar artery distribution, but of CNs IX and X; LST; descending ipsilateral corneal reflex; weakness of more often due to vertebral artery sympathetic fibers; vestibular nuclei; ipsilateral soft palate; loss of ipsilateral occlusion This document was downloaded for personal use only. Unauthorized distribution is strictly prohibited. inferior cerebellar peduncle; afferent gag reflex; paralysis of ipsilateral vocal spinocerebellar tracts; lateral cord; ipsilateral central Horner’s cuneate nucleus syndrome; nystagmus; cerebellar ataxia of ipsilateral limbs; lateropulsion Adapted from Campbell.1 AICA, anterior inferior cerebellar artery; CN, cranial nerve; SCA, spinocerebellar ataxia. central pontine myelinolysis, Arnold–Chiari malforma- have telltale clues such as long tract signs, gaze palsies, tions, and syringobulbia. Considering that the brainstem internuclear ophthalmoplegia, and complex spontaneous is such a compact structure, with cranial nerve nuclei, eye movement abnormalities. Focal brainstem lesions are nerve fascicles, and long ascending and descending tracts often characterized by ‘‘crossed’’ syndromes, consisting of all closely juxtaposed, a plethora of clinical findings are ipsilateral cranial nerve dysfunction and contralateral usually present to help in localization. Most brainstem long motor or sensory tract dysfunction. Due to the cases with involvement of multiple cranial nerves will rich vestibular and cerebellar connections, patients with MULTIPLE CRANIAL NEUROPATHIES/CARROLL, CAMPBELL 55 brainstem disease will often complain of vertigo, skull base. Next, a brief discussion of extramedullary gait unsteadiness, ataxia, discoordination, nausea, and vascular etiologies, bone disorders, and traumatic con- vomiting. Thus, a history aimed at eliciting these symp- siderations as well as peripheral nerve considerations will toms as well as a careful complete neurologic exam ensue. Finally, disorders of specific cranial nerve groups/ looking for these associated signs is necessary to aid in syndromes will be discussed. localizing a process to the brainstem. CHRONIC MENINGITIS MULTIPLE CRANIAL NEUROPATHIES: OVERVIEW Infectious Meningitis There are 12 pairs of