Migraine with prolonged aphasic aura associated with a CACNA1A mutation: A case report and narrative review

OBJECTIVE

To demonstrate that a known CACNA1A variant is associated with a phenotype of prolonged aphasic aura without hemiparesis.

BACKGROUND

The usual differential diagnosis of prolonged aphasia without hemiparesis includes vascular disease, seizure, metabolic derangements, and migraine. Genetic mutations in the CACNA1A gene can lead to a myriad of phenotypes, including familial hemiplegic migraine (FHM) type 1, an autosomal dominant disorder characterized by an aura of unilateral, sometimes prolonged weakness. Though aphasia is a common feature of migraine aura, with or without hemiparesis, aphasia without hemiparesis has not been reported with CACNA1A mutations.

METHODS

We report the case of a 51-year-old male who presented with a history of recurrent episodes of aphasia without hemiparesis lasting days to weeks. His headache was left sided and was heralded by what his family described as "confusion." On examination, he had global aphasia without other focal findings. Family history revealed several relatives with a history of severe headaches with neurologic deficits including aphasia and/or weakness. Imaging revealed T2 hyperintensities in the left parietal/temporal/occipital regions on MRI scan with corresponding hyperperfusion on SPECT. Genetic testing revealed a missense mutation in the CACNA1A gene.

CONCLUSIONS

This case expands the phenotypic spectrum of the CACNA1A mutation and FHM to include prolonged aphasic aura without hemiparesis. Our patient's SPECT imaging demonstrated hyperperfusion in areas correlating with aura symptoms which can occur in prolonged aura.

The Inverse Lhermitte Phenomenon Suggests Nitrous Oxide-Induced Myelopathy: Case Report and Review of the Literature

Nitrous oxide-induced myelopathy is a relatively well-known clinical entity. Less well-known, however, is the rare inverse Lhermitte phenomenon, where neck flexion elicits an ascending, rather than descending, electric shock-like sensation. This is a characteristic symptom and sign that may occur in nitrous oxide toxicity. In this article, we present the case of a patient who was admitted to our hospital with suspected Guillain-Barré syndrome due to her ascending numbness and unsteady gait. We describe her examination and laboratory features leading to the correct diagnosis, along with a historical review of the various subtypes of the Lhermitte phenomenon and the pathophysiology of nitrous oxide-induced myelopathy.

Nerve entrapments related to muscle herniation

BACKGROUND

Muscle herniation is a muscle protrusion through a fascial defect. It is a rarely reported cause of nerve entrapment.

METHODS

We present a case of superficial fibular (peroneal) neuropathy associated with a fibularis (peroneus) brevis muscle herniation and a review of the literature on nerve entrapments secondary to muscle herniation unrelated to compartment syndrome.

RESULTS

Eleven cases of nerve entrapments secondary to muscle herniation were identified. The superficial fibular nerve (SFN) was the most commonly entrapped nerve by fibularis muscle herniation. Patients presented with pain, numbness, or paresthesias, and an often tender, small palpable mass with a Tinel sign. Muscle MRI or ultrasound identified the lesion, and patients responded well to fasciotomy.

CONCLUSIONS

The most commonly reported nerve entrapped by muscle herniation is the SFN secondary to fibularis muscle herniation. Characteristic clinical and imaging (MRI or ultrasound) features are diagnostic, and there is a salutary response to fasciotomy.

Neuropathic cachexia associated with type 1 diabetes in an adolescent girl

BACKGROUND

Diabetic neuropathic cachexia is a rare and little understood variant of diabetic neuropathy. It predominantly affects men with type 2 diabetes mellitus in their sixth to seventh decades of life and is characterized by the subacute onset of a painful sensory neuropathy, rapid weight loss, and psychiatric comorbidity.

METHODS

We present the only female pediatric case described to date, and one of only a handful of cases reported to affect type 1 diabetics.

RESULTS

In this patient a diagnosis of diabetic neuropathic cachexia was based on the rapid onset of severe allodynic pain, polyneuropathy, and marked weight loss in the setting of poorly controlled diabetes, without evidence of end-organ disease and exclusion of other known causes of neuropathy.

CONCLUSIONS

Diabetic neuropathic cachexia is a complex neuroendocrinologic disorder characterized by profound weight loss, neuropathic pain, and mood disturbance. Electrodiagnostic abnormalities were pronounced showing a moderately severe generalized sensorimotor polyneuropathy.

Teaching video neuroimages: orthostatic tremor: the helicopter sign

A 63-year-old man presented with 4 years of orthostatic tremor while standing, resolving after sitting or leaning against a wall. There was marked subjective unsteadiness, but no falls. Surface EMG in arms and legs demonstrated a 14- to 16-Hz synchronous tremor in antagonist muscles (video on the Neurology Web site at www.neurology.org.).

Carpal tunnel syndrome in older adults

The clinical and electrophysiologic characteristics of carpal tunnel syndrome (CTS) in elderly adults are not well established. We examined age differences in clinical, functional, and electrophysiologic features in elderly adults referred to a neuromuscular service for evaluation of symptoms suggestive of CTS. Of 415 consecutive subjects referred over an 18-month period, 343 met clinical criteria for CTS. There were 158 young (<or=50 years), 115 middle-aged (51-64 years), and 70 elderly adults (>or=65 years). There were no age differences in the duration of CTS symptoms, hand function, or presence of autonomic symptoms. The elderly adults had a higher prevalence of thenar weakness and thenar atrophy than younger subjects. Electrophysiologic abnormalities were more common and more severe in the older subjects. Our study shows that although there are no age differences in subjective complaints of CTS, older adults had objective clinical and electrophysiologic evidence of a more severe median nerve entrapment. The findings suggest that greater attention needs to be paid to objective evidence of CTS severity rather than subjective complaints when evaluating elderly adults presenting for clinical evaluation of CTS.

Occupational manganese neurotoxicity provoked by hepatitis C

Manganese neurotoxicity developed in a highly exposed worker after asymptomatic, moderate hepatic dysfunction from hepatitis C infection. Antiviral therapy was accompanied by resolution of increased blood manganese levels and neurologic improvement. Even asymptomatic hepatic dysfunction may impair manganese clearance and place highly exposed persons at risk for toxicity.

Methyl bromide intoxication causes reversible symmetric brainstem and cerebellar MRI lesions

Methyl bromide is toxic to the central and peripheral nervous systems. A patient with occupational exposure to this agent is described. MRI showed strikingly symmetric brainstem and cerebellar lesions. The patient's clinical course and the topography and resolution of his MRI abnormalities suggest that this condition is an energy deprivation syndrome.

Blood ?? T cells,Campylobacter jejuni, and GM1 titers in Guillain-Barr� syndrome

The gammadelta T cells participate in microbial defense, are prevalent in intestinal epithelia, and are activated in autoimmune diseases. We studied whether peripheral blood gammadelta cells and gammadelta subsets are increased in Guillain-Barré syndrome (GBS) and whether elevations are associated with Campylobacter jejuni infection or GM1 elevations. In 20 GBS patients, we performed serial flow cytometry studies of blood gammadelta, Vdelta1, and Vdelta2 cells (+/- CD8+), C jejuni, and ganglioside titers. There was no significant difference in median gammadelta T-cell percentages between GBS patients and controls at onset and at convalescence. However, 5 patients had marked Vdelta1/CD8+ elevations. Elevated Vdelta1 or Vdelta1/CD8+ cells occurred in 3 of 6 patients with C jejuni or GM1 titer elevations. A minority of GBS patients have elevations of Vdelta1/CD8+ cells, possibly associated with elevated C jejuni or GM1 titers. The gammadelta T cells may have a cytotoxic (or suppressor) role in the disease.

Peripheral neuropathy in young-old and old-old patients

Diabetes is said to account for most cases of neuropathy in the elderly. We reviewed records of 223 young-old (65-79 years) and 77 old-old (>or=80 years) patients referred for evaluation of neuropathic symptoms over a 9-year period. We prospectively validated our findings in 102 consecutive elderly (77 young-old) patients receiving intensive evaluation for neuropathy. Diabetes was the most common cause of neuropathy (41%), but was less common in the old-old (25% versus 46%, P < 0.001). Idiopathic neuropathies were more common in the old-old (39% versus 9%, P < 0.001). Alcoholic and nutritional neuropathies were uncommon in the old-old. Electrophysiological studies showed that most patients had an axonal type of neuropathy. Sural and peroneal response amplitudes were poorly correlated with age. We obtained similar results in our prospective study. The distribution of causes of neuropathies in young-old and old-old patients, in a hospital-based sample, is age-related. Future studies need to include the old-old to better understand the nature of neuropathy in the elderly.

Electrophysiologic correlates of weakness in L5/S1 radiculopathy

INTRODUCTION

Management of patients with radiculopathy involves estimating the degree of physiologic and anatomic injury, and weighing that to predict the likely clinical course.

OBJECTIVE

To determine whether low distal peroneal and tibial CMAP amplitudes correlate with weakness and fibrillations of functionally relevant muscles in L5/S1 radiculopathy (LSR).

METHODS

We reviewed clinical and electrophysiologic data in 66 consecutive patients with LSR.

RESULTS

A significantly greater number of patients with low peroneal CMAP amplitudes had weakness of L5 (p = 0.025) and S1 innervated leg muscles (p < 0.001). Low tibial CMAP amplitudes were also associated with weakness of S1 innervated muscles (p < 0.038). The association of low peroneal CMAP amplitudes with weakness persisted when weakness of at least 3 muscles was considered in the analysis for L5 (p < 0.0001) and S1 (p = 0.014) innervated muscles.

CONCLUSIONS

Low peroneal and tibial CMAP amplitudes may serve as surrogate measures for segmental weakness of functionally relevant muscles in LSR.

Miller Fisher syndrome: axonal, demyelinating or both?

Controversy exists concerning whether Miller Fisher syndrome (MFS) is the result of a predominantly axonal or demyelinating polyneuropathy and whether the Guillain-Barré syndrome variant of acute ataxia and areflexia without ophthalmoplegia, ataxic Guillain-Barré syndrome (atxGBS), has a distinct pathophysiology. We explored these issues by reviewing the electrophysiologic features of 6 patients with MFS and 2 patients with atxGBS. EMG laboratory records were reviewed and electrophysiologic findings were categorized as axonal or demyelinating neuropathy using previously defined criteria. Of the 6 patients with MFS, 5 had electrophysiologic evidence suggestive of an axonal, predominantly sensory polyneuropathy; only 1 patient met criteria for demyelinating polyneuropathy. Both patients with atxGBS had demyelinating sensorimotor polyneuropathy. Electrophysiologic abnormalities in MFS typically suggest a predominantly axonal, sensory polyneuropathy, though demyelinating forms occur and may be under-diagnosed using current criteria. AtxGBS, in our experience, is a predominantly demyelinating polyneuropathy.

Autonomic dysfunction in idiopathic carpal tunnel syndrome

While the sensorimotor features of carpal tunnel syndrome (CTS) are well known, a prospective, systematic study of autonomic disturbances in CTS is lacking. Of 139 limbs with CTS (76 patients), autonomic symptoms were reported in 76 (47 patients). Of these, 59% consisted of swelling of the fingers, 39% dry palms, 33% Raynaud's phenomenon, and 32% blanching of the hand. Sympathetic skin response (SSR) had a sensitivity/specificity ratio of 34/89% in CTS with autonomic symptoms. The presence of autonomic disturbances was significantly associated with female gender (odds ratio 4.06, 95% CI 1.5-11.4, P = 0.007), SSR abnormalities (odds ratio 4.3, 95% CI 1. 6-11.4, P = 0.003), and severity of electromyographic findings (odds ratio 1.8, 95% CI 1-3.3, P = 0.04) but not age, duration of disease, or clinical severity in a binary logistic regression model. Autonomic disturbances are common (55%) in CTS, occurring with increasing severity of electrophysiologic findings.

Prevalence of peripheral neuropathy in injection drug users

BACKGROUND

Nucleoside analogue reverse transcriptase inhibitors are a critical component of antiretroviral therapy in HIV-infected persons. Several of these medications cause painful, dose-limiting peripheral neuropathy (PN), which may develop earlier and more intensely in persons with preexisting neuropathy. The prevalence of baseline peripheral neuropathy in injection drug users (IDUs), one of the largest populations of HIV-infected persons, has not been described, yet has important implications for the selection of antiretroviral therapy.

METHODS

The authors performed a cross-sectional study of PN in 212 HIV-seronegative and HIV-seropositive IDUs using detailed neurologic histories, physical examinations, quantitative electrophysiologic study, and quantitative sensory testing. Data were used to assign patients to one of four positive categories of PN or one of two negative categories.

RESULTS

PN was present in 24.5% of HIV-seronegative IDUs, three to four times the reported frequency for HIV-seronegative persons in the general or male homosexual population. PN was present in 32.1% of HIV-seropositive patients. PN was axonal in nature and associated with increased age and alcohol use. PN was asymptomatic in 81% of HIV-seronegative and 71% of HIV-seropositive patients with PN.

CONCLUSIONS

There is a high prevalence of PN in HIV-seronegative IDUs. Although these PNs do not seem to predispose HIV-seropositive IDUs to HIV-related PN, they may increase the likelihood of iatrogenic neuropathy. Intravenous drug users may need more diligent monitoring when administered nucleoside analogues than patients in risk groups with lower endemic rates of PN.

Treatment of mononeuropathy multiplex in hepatitis C virus and cryoglobulinemia

Recent reports advocate alpha-interferon (alpha-Ifn) treatment for mononeuropathy multiplex in hepatitis C virus-associated cryoglobulinemia. We report 2 patients with this disorder to describe two underrecognized treatment outcomes--worsening of polyneuropathy with initiation of alpha-Ifn, in the absence of immunosuppression, and deterioration of liver function with prednisone, despite improvement of polyneuropathy.

Median mixed and sensory nerve conduction studies in carpal tunnel syndrome

OBJECTIVE

To assess the sensitivities and specificities of velocity differences between median mixed nerve conduction across the wrist (Medmxpw) and (I) median mixed nerve conduction in the forearm (Medmxf) and (II) palm to D2 sensory conduction (MedpD2).

DESIGN AND METHODS

We prospectively studied 67 limbs of patients with clinically definite carpal tunnel syndrome (CTS). Medmxf and Medmxpw were performed by stimulating the median nerve at the elbow and palm respectively and recording at the proximal wrist crease. We also compared conventional median sensory (D2-wrist) and mixed (palm-wrist) tests in all patients. Thirty limbs of asymptomatic subjects served as normal controls and 21 limbs of subjects with other neuropathies served as diseased controls; control data was collected prospectively.

RESULTS

The sensitivity of the MedpD2-Medmxpw difference (0.87) was significantly greater than that of the Medmxf-Medmxpw difference (0.61, P < 0.001). Both tests were similar and highly specific (0.98 and 0.96, respectively).

CONCLUSIONS

The MedpD2-Medmxpw study is among the most sensitive and specific electrophysiologic tests for CTS.

Low-dose, short-term oral prednisone in the treatment of carpal tunnel syndrome

We evaluated the effectiveness of low-dose, short-term oral prednisone in ameliorating the pain and other symptoms of carpal tunnel syndrome (CTS) in a randomized, double-blind, placebo-controlled study of patients with mild to moderate CTS. Prednisone, in doses of 20 mg daily for the first week and 10 mg daily for the second week, resulted in significant improvement in global symptom scores. The effect was rapid, but gradually waned over 8 weeks of observation. This approach may provide a treatment alternative in the short-term, conservative management of CTS.

Late motor involvement in cases presenting as "chronic sensory demyelinating polyneuropathy"

Chronic inflammatory demyelinating polyneuropathy (CIDP) is usually characterized by prominent motor deficits. A pure sensory presentation, labeled chronic sensory demyelinating neuropathy (CSDN), has been reported, but it is unclear if this neuropathy is a distinct clinical and immunologic entity or merely the sensory presentation of the more usual sensorimotor CIDP. We describe 5 patients with what initially appeared to be CSDN; 3 subsequently developed substantial weakness coincident with the electrophysiologic appearance of multifocal motor conduction block. These cases indicate that, in some cases, CSDN may be a transitional clinical stage of CIDP in which the more usual sensorimotor deficits develop later. Immune-based therapy, including intravenous immunoglobulin, was found to be effective in both the pure sensory and sensorimotor types.

Headache characteristics in hospitalized patients with Lyme disease

We reviewed 49 patients consecutively hospitalized for neurologic Lyme disease to determine the frequency and characteristics of recent onset headaches in this group. All patients had positive serum Lyme ELISAs and other neurologic illness excluded. Recent-onset headache occurred in 26 of 49 patients (53%). Patients with headaches more commonly had central nervous system involvement (54% vs 19%, P < .05) and flu-like illness (58% vs 19%, P < .0005). Eight of 26 (31%) met criteria for meningitis or encephalitis with abnormal CSF examinations. All 8 had focal findings (6), cognitive dysfunction (1), or both (1). The remaining 18 patients had recent-onset headaches resembling migraine (9), tension-type headache (5), or neither (4). Antibiotic treatment resulted in complete headache resolution in 11 of 14 patients with available follow-up data. Based on these findings, we conclude that recent-onset headaches are common in patients hospitalized with Lyme disease. Of those with meningitis or encephalitis requiring intravenous antibiotics, all had focal neurologic findings or cognitive abnormalities, not just headaches.

Transient worsening of optic neuropathy as a sequela of the Jarisch-Herxheimer reaction in the treatment of Lyme disease

A 58-year-old woman developed neurologic and neuroophthalmologic manifestations of Lyme disease, including a radiculomyelitis, cranial neuritis and mild right optic neuropathy. Upon treatment with intravenous ceftriaxone a Jarisch-Herxheimer reaction occurred with encephalopathy, mild fever, worsening radiculomyelitis, and deterioration of her visual acuity. Intravenous methylprednisolone was given, and the visual acuity recovered over 72 hours. This case suggests that transient worsening of optic neuropathy can develop as a sequela of the Jarisch-Herxheimer reaction in the treatment of Lyme disease.

Central pain from cerebral abscess: thalamic syndrome in AIDS patients with toxoplasmosis

We describe two patients with acquired immunodeficiency syndrome (AIDS) who developed classic thalamic syndrome (TS) due to Toxoplasma abscesses in the thalamic region. Treatment with amitriptyline provided substantial relief in both patients. Postmortem examination in one case revealed a lesion in the internal capsule and thalamic reticular nucleus. These observations indicate that (1) TS can result from an isolated lesion in the internal capsule and reticular nucleus of the thalamus, (2) cerebral abscess can cause classic TS, (3) central pain can be added to the many pain syndromes that afflict AIDS patients, and (4) an analgesic response to amitriptyline is possible in these patients.

Chronic paroxysmal headache: two cases with cerebrovascular disease

Paroxysmal headaches often occur in benign headache disorders such as episodic cluster headache, chronic paroxysmal hemicrania (CPH) and episodic paroxysmal hemicrania. We report 2 patients with paroxysmal headaches occurring in association with cerebrovascular disease. The first patient had paroxysmal headaches from an arteriovenous malformation which resolved following embolization. In the second patient, headache followed a cerebral infarction and responded to treatment with indomethacin. We suggest that vascular disease may cause paroxysmal headaches resembling CPH. Patients with an atypical presentation of CPH warrant a neuroimaging procedure.

Neuro-Behçet's disease: CT and clinical correlates

We examined the serial CTs and clinical courses of five patients with neuro-Behçet's disease and reviewed ten previously reported cases, all with focal CT abnormalities. The CT lesions were in the brainstem (8 patients), basal ganglia (7), thalamus (4), or hemispheric white matter (7). Of the 13 patients who received contrast, nine had lesions that showed enhancement. In five, lesions were visualized with contrast that were not apparent without it. The CT lesions were usually accompanied by corresponding clinical deficits, although in some patients deficits were more extensive than the CT predicted. In nine patients, contrast enhancement decreased or disappeared over days to weeks, often with associated clinical improvement. In eight patients followed serially, CT abnormalities resolved completely or substantially. Based on these cases, we conclude that (1) CT abnormalities of gray and white matter occur commonly in neuro-Behçet's disease with focal deficits, and help support the diagnosis; (2) CT abnormalities, particularly contrast enhancement, correlate well with the activity of parenchymal disease; and (3) the concomitant improvement of clinical and CT abnormalities with resolution of contrast enhancement suggests that partially reversible inflammatory changes associated with breakdown of the blood-brain barrier may produce some of the neurologic and radiographic deficits in this illness.