Neil L. Rosenberg

Neurologic sequelae of chronic solvent vapor abuse

Neurologic abnormalities were seen in 13 of 20 patients with a history of chronic solvent vapor (primarily toluene) abuse for 2 or more years. The patients were evaluated after an abstinence period of at least 4 weeks, to avoid neurologic effects of acute intoxication. Neurologic signs included cognitive (60%), pyramidal (50%), cerebellar (45%), and brainstem/ cranial nerve (25%) findings. Eight of nine CTs revealed diffuse atrophy of cerebral hemispheres, cerebellum, and brainstem. BAERs were abnormal in three of four patients, and EEG abnormalities were seen in three of seven patients. Chronic exposure to solvent vapor may cause persistent neurologic impairment.

Neuropsychologic impairment and MRI abnormalities associated with chronic solvent abuse.

Objective: Individuals chronically abusing organic solvents have been reported in the medical literature for almost four decades to have a variety of neurological abnormalities. Most have been single case reports or studies in small numbers of individuals. The purpose of this study was to evaluate the neurologic and neuropsychologic effects of chronic solvent abuse in a larger group of individuals and compare the results to a control group of other drug abusers. Attempts to estimate a dose–response relationship between solvent abuse and either neuropsychological tests or magnetic resonance imaging (MRI) abnormalities were also undertaken. Methods: A sample of 55 solvent abusers was compared to a sample of 61 users of other drugs, especially cocaine and alcohol, on a battery of cognitive and neuropsychological tests. Fifty of the solvent abusers and 51 members of the comparison sample also underwent MRI of the brain. Comparisons were made by means of multivariate analysis of variance and covariance. Results: Compared to the general population, both groups performed poorly, scoring below the mean on most neuropsychological measures. Solvent abusers performed more poorly than the comparison sample on measures of working memory and executive cognitive functions. Both groups showed evidence of abnormal MRI findings, but a greater percentage of the solvent abuse group showed such abnormalities. No clear dose–response relationship was seen between solvent abuse and abnormalities on neuropsychological tests, but a strong dose–response relationship was seen in the presence of MRI abnormalities. Conclusion: The findings in this study document widespread cognitive impairment, which could not be attributed to the effects of solvents entirely. These findings expand upon previous data regarding neurological abnormalities in solvent abusers, by demonstrating a dose–response relationship with MRI abnormalities. An unexpected finding was the high prevalence of neuropsychological impairment and MRI abnormalities among the comparison group. The results of this study has implications regarding low-level solvent exposure, as in the occupational setting, suggesting that MRI may be a more useful tool to sort out the presence of neurological abnormalities rather than neuropsychological tests. Since no dose–response relationship was seen between solvent abuse and neuropsychological testing, reliance upon these tests in assessing neurological injury from solvents is a highly dubious practice.

Cyanide‐induced parkinsonism Clinical, MRI, and 6‐fluorodopa PET studies

A 46-year-old man ingested 1,500 mg of potassium cyanide in a suicide attempt. He survived, but later developed a severe parkinsonian syndrome. MRI revealed multiple areas of low-signal intensity in the globus pallidus and posterior putamen. A 6-fluorodopa PET study revealed bilateral decreased uptake in the basal ganglia. This evidence of functional impairment of dopaminergic nigrostriatal neurons is related either to direct toxicity of cyanide or to the effects of cerebral hypoxia secondary to cyanide intoxication.

Central nervous system effects of chronic toluene abuse—Clinical, brainstem evoked response and magnetic resonance imaging studies

We describe the results of neurological evaluation, magnetic resonance imaging (MRI) of the brain and brainstem auditory evoked response (BAER) testing in 11 chronic toluene vapor abusers. Neurological abnormalities were seen in four of 11 individuals and included cognitive, pyramidal, cerebellar and brainstem findings. MRI of the brain was abnormal in three of 11 individuals and revealed the following abnormalities: 1) Diffuse cerebral, cerebellar, and brainstem atrophy; 2) Loss of differentiation between the gray and white matter throughout the CNS; and 3) Increased periventricular white matter signal intensity on T2 weighted images. BAERs were abnormal (control mean +/- 3 S.D.) in five of 11 individuals. As a group, the latency of V (p less than 0.01), the III-V interpeak (p less than 0.05) and the I-V interpeak latencies were prolonged compared to controls. All three individuals with abnormal MRI scans also had abnormal neurological examinations and BAERs. Two of five individuals with abnormal BAERs, however, had normal neurological examinations and MRI scans. Our data support previous findings of diffuse white matter involvement in chronic toluene abusers and suggest that BAERs may detect early CNS injury from toluene inhalation even at a time when neurological examination and MRI scans are normal. BAERs, therefore, may be a sensitive screening test to monitor individuals at risk from toluene exposure (either abusers or industrially exposed individuals) for early evidence of CNS injury.

Infarction of abducens nerve fascicle as cause of isolated sixth nerve palsy related to hypertension.

Isolated sixth nerve pahies are most frequently c a d by focal lesions of the nerve in the cavernous ~inue, superior orbital fissure, or subarachnoid space, in patients with hypertension or diabetes mellitua.1 Pathologic confirmation of the lesions is lacking. Sixth nerve paleien resulting from a lesion of the intrapontine abducens nerve fascicle are rare and felt to be universally associated with other signs of pontine dysfunction (references 2 through 5, and R.B. Damff, personal communication). We report a case of an isolated abducens nerve paley in a hypertensive man, with no other identifiable etiology, who had a pontine infarct Been on CT involving the abducens nerve fascicle. Case report. A 61-year-old man with a history of poorly controlled hypertension awoke with new onset of horizontal diplopia. For the previous 1 to 2 days, he had noted periorbital pain, which had abated prior to the development of diplopia. There was no history of head trauma, diabetes mellitus, or any other syatemic disorder. He first sought medical attention when his diplopia failed to clear after 2 weeks. His examination was entirely normal except for a complete left sixth nerve palsy. The rest of his extraocular movements were full, and no nyatagmue or internuclear ophthalmoplegia was seen. Pupile were equal and reacted briskly to liiht both directly and consensually, as well as to accommodation. There was no p h i s . Sensation in the first division of V was intact. Facial muscles and muecles of mastication were of normal strength. The rest of the neurologic examination was normal. CTofthe head showeda 5 X 8 mm*, well-defined, low-density lesion in the left midpons between the fourth ventricle and cerebral aqueduct near the midline, which did not enhance and was felt to be consistent with an infarction (figure). The remainder of the CT was normal, with no evidence of aneurysm, intraorbital maeeee, bone emion, or other abnormality of the superior orbital fissure. Follow-up 4 month later revealed complete resolution of his sixth nerve palsy, although a repeat CT revealed persistence of the pontine lesion. Discussion. The present case indicates that an isolated abducene palsy may result from a well-placed pontine infarction that involves the abducene nerve fascicle but does not damage enough of the BUTrounding tiesue to result in other neurologic signs or symptom. The lesion would have to be ventral to the pontine paramedian reticular formation and dorsal to the corticoepinal tracts in the h i s pontis. Radiologic evaluation of isolated abducens nerve palsies in individuals with systemic vascular disease is warranted.

Therapeutic effects of human fetal dopamine cells transplanted in a patient with Parkinson's disease.

Publisher Summary This chapter examines the therapeutic effects of human fetal dopamine cells transplanted in a patient with Parkinsons disease. The patient was a 52 years old male with a 20 year history of Parkinsons disease that presented with left-sided symptoms. The left side remained the more impaired. The patient suffered from the on-off phenomenon and freezing spells. The patient underwent clinical evaluation by a neurologist using the Hoehn and Yahr scale and the Unified Parkinsons Disease Rating Scale (UPDRS) for motor performance and activities of daily living. The patient received broad-spectrum antibiotics at the time of surgery and for 10 days thereafter. Prophylactic phenytoin was also used. Beginning about 30 days and peaking at 60 days after surgery, the patient demonstrated bilateral increases in finger speed both before and after the first morning dose of drugs. There was a greater improvement in his response to drugs than in his basal performance. Data were analyzed in 2 month intervals and compared to pre-operative. Results of the two-way analysis of variance showed highly significant improvement in drug response after surgery for all periods.

Computerized tomography and pure Sensory stroke

we studied three patients fitting the clinical syndrome of ‘pure sensory’ stroke. The abnormalities on computerized tomography (CT) scan differed and included posterior cerebral artery occlusion, lacunar infarct in the thalamocortical pathway, and hemorrhage in the thalamus. These cases were unique in that CT scan abnormalities were found in patients with pure sensory stroke.

Intensive Rehabilitative Approach to Eosinophilia Myalgia Syndrome Associated With Severe Polyneuropathy

We report a case of the eosinophilia myalgia syndrome (EMS) with incapacitating myalgias, weakness secondary to a severe polyneuropathy, and contractures in all four extremities requiring aggressive rehabilitation treatment. A 55-year-old woman was admitted to a rehabilitation hospital 11 months after the onset of EMS. At that time, she had severe weakness secondary to peripheral neuropathy and painful contractures in all extremities and required high doses of narcotics for pain control. A continuous passive range of motion machine was used in order to maintain range of motion obtained during active exercise therapy. The patient showed functional improvement in basic mobility and ADL skills. She was withdrawn from narcotics and successfully learned pain management techniques. An aggressive rehabilitation approach in the treatment of EMS associated with peripheral neuropathy may improve functional outcome even when instituted late in the clinical course.

Coronavirus SD-Induced Immunoregulatory Disturbances in a Murine Model of Demyelination

We previously reported the isolation of coronaviruses while working with autopsy tissue from patients with multiple sclerosis1 and have been investigating the pathogenesis of these viruses in mice. Inoculation of three to four week old C57BL/6 mice with coronavirus SD induces a syndrome characterized by hindlimb anesthesia, paresis, or both between 4 and 9 days post-infection.2 We now report the finding of an unusual immunologic derangement in these mice.

Treatment of refractory chronic demyelinating polyneuropathy with lymphoid irradiation

Four patients with refractory or poorly responsive chronic progressive demyelinating polyneuropathy (CPDP) were treated with total lymphoid irradiation (total dose, 2000 rad) in an uncontrolled feasibility study. All patients had previously failed conventional therapy for CPDP, as well as other unconventional treatments. During a follow-up period of 7 to 12 months after total lymphoid irradiation, there was a profound and sustained suppression of the absolute lymphocyte count and in vitro lymphocyte function, as well as an increase in the ratio of Leu-2 (suppressor/cytotoxic subset) to Leu-3 (helper/inducer subset) T cells in the blood. Three of the four patients demonstrated improvement in distal muscle strength, and this was associated with increased functional capabilities in two patients. In contrast, no clinical improvement in sensation was noted in any patient. Nerve conduction studies showed patchy improvement in three patients. The results of this preliminary uncontrolled study indicate that radiotherapy deserves further study in the treatment of CPDP.