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Biomedical subjects

M H Silber

Publications and source records attributed to M H Silber.

At least 19 recordsLinked to original sources

Synucleinopathy pathology and REM sleep behavior disorder plus dementia or parkinsonism.

OBJECTIVE: To determine if synucleinopathy pathology is related to REM sleep behavior disorder (RBD) plus dementia or parkinsonism. METHODS: The clinical and neuropathologic findings were analyzed on all autopsied cases evaluated at Mayo Clinic Rochester from January 1990 to April 2002 who were diagnosed with RBD and a neurodegenerative disorder. Ubiquitin and/or alpha-synuclein immunocytochemistry was used in all cases. The clinical and neuropathologic diagnoses were based on published criteria. RESULTS: Fifteen cases were identified (14 men). All had clear histories of dream enactment behavior, and 10 had RBD confirmed by polysomnography. RBD preceded dementia or parkinsonism in 10 (66.7%) patients by a median of 10 (range 2 to 29) years. The clinical diagnoses included dementia with Lewy bodies (DLB) (n = 6); multiple-system atrophy (MSA) (n = 2); combined DLB, AD, and vascular dementia (n = 1); dementia (n = 1); dementia with parkinsonism (n = 1); PD (n = 1); PD with dementia (n = 1); dementia/parkinsonism/motor neuron disease (n = 1); and AD/Binswanger's disease (n = 1). The neuropathologic diagnoses were Lewy body disease (LBD) in 12 (neocortical in 11 and limbic in 1) and MSA in 3. Three also had argyrophilic grain pathology. In the LBD cases, concomitant AD pathology was present in six (one also with Binswanger's pathology, and one also with multiple subcortical infarcts). CONCLUSION: In the setting of degenerative dementia or parkinsonism, RBD often reflects an underlying synucleinopathy.

Age of Onset↗

Narcolepsy associated with other central nervous system disorders.

The authors identified patients with the coexistence of narcolepsy and another CNS disorder seen between 1975 and 1998 at their institution. Eighteen patients were identified, nine with narcolepsy commencing within 1 year before or after the other disorder. Seven patients (39%) had hypothalamic-pituitary syndromes. When they occur together, narcolepsy and other CNS disorders frequently emerge at about the same time, suggesting a causative relationship. Hypothalamic-pituitary pathology was the most common association.

Brain↗

Basal forebrain malformation with hyperhidrosis and hypothermia: variant of Shapiro's syndrome.

A 62-year-old woman presented with episodic sweating and shivering with reduced core temperature. Brain MRI demonstrated a basal forebrain malformation. Physiologic testing included EEG, SPECT, heat challenge, and autonomic testing. Glycopyrrolate aborted spells and raised core temperature. Hypothalamic dysregulation is likely the primary pathophysiology in the setting of other forebrain anomalies. These findings expand the structural abnormalities and treatment options within the temperature dysregulating conditions of Shapiro's syndrome and "diencephalic epilepsy."

Female↗

Association of REM sleep behavior disorder and neurodegenerative disease may reflect an underlying synucleinopathy.

Our objective was to examine whether rapid eye movement (REM) sleep behavior disorder occurs in disproportionally greater frequency in multiple system atrophy (MSA), Parkinson's disease (PD), and dementia with Lewy bodies (DLB), collectively known as the synucleinopathies, compared to other nonsynucleinopathy neurodegenerative disorders. In study 1, we reviewed the clinical records of 398 consecutive patients evaluated at Mayo Clinic Rochester for parkinsonism and/or cognitive impairment. The frequency of suspected and polysomnogram (PSG)-confirmed REM sleep behavior disorder (RBD) among subjects with the synucleinopathies MSA, PD, or DLB was compared to the frequency among subjects with the nonsynucleinopathies Alzheimer's disease (AD), frontotemporal dementia (FTD), corticobasal degeneration (CBD), progressive supranuclear palsy (PSP), mild cognitive impairment (MCI), primary progressive aphasia (PPA), and posterior cortical atrophy (PCA). In study 2, we reviewed the clinical records of 360 consecutive patients evaluated at Mayo Clinic Jacksonville for parkinsonism and/or cognitive impairment. The frequency of probable RBD among patients with PD and DLB was compared to the frequency among patients with AD and MCI. In study 3, we reviewed the brain biopsy or postmortem autopsy diagnoses of 23 Mayo Clinic Rochester patients who had been clinically examined for possible RBD and a neurodegenerative disorder. In study 1, patients with MSA, PD, or DLB were more likely to have probable and PSG-confirmed RBD compared to subjects with the nonsynucleinopathies (probable RBD 77/120=64% vs. 7/278=3%, p < 0.01; PSG-confirmed RBD 47/120=39% vs. 1/278=0%, p < 0.01). In study 2, patients with PD and DLB were more likely to have probable RBD compared to those with AD and MCI (56% vs. 2%, p < 0.01). In study 3, of the 23 autopsied patients who had been questioned about possible RBD, 10 were clinically diagnosed with RBD. The neuropathologic diagnoses in these 10 included Lewy body disease in nine, and MSA in one. Of the other 13 cases, 12 did not have a history suggesting RBD, and the one case who did had normal electromyographic atonia during REM sleep on PSG and autopsy findings of PSP. Only one of these 13 had a synucleinopathy. The positive predictive values for RBD indicating a synucleinopathy for studies 1-3 were 91.7%, 94.3%, and 100.0%, respectively. Clinically suspected and PSG-proven RBD occurs with disproportionally greater frequency in MSA, PD, and DLB compared to other neurodegenerative disorders. In the setting of degenerative dementia and/or parkinsonism, we hypothesize that RBD is a manifestation of an evolving synucleinopathy.

Adult↗

Narcolepsy: new understanding of irresistible sleep.

Recently, low levels of a newly identified neuropeptide, hypocretin 1, were described in the cerebrospinal fluid of patients with narcolepsy. This neurochemical finding furthers our understanding of this enigmatic sleep disorder typically characterized by excessive daytime sleepiness, cataplexy, sleep paralysis, and hypnagogic hallucinations. Narcolepsy appears to be fundamentally related to abnormally regulated rapid eye movement sleep. The diagnosis of this disorder remains challenging because of multiple other conditions that can cause daytime sleepiness and the difficulties in recognizing cataplexy based on patient report. The role of hypocretins in narcolepsy is unclear but intriguing because the cell bodies are restricted to the lateral hypothalamus, a brain region long associated with sleep regulation, with neuronal widespread projections to areas including the locus ceruleus, ventral tegmental area, amygdala, and dorsal raphe. Hypocretins potentially modulate the activity of monoamines and acetylcholine, and therefore their absence leads to the multiple symptoms of narcolepsy. This article reviews the current understanding of the diagnosis and treatment of narcolepsy and discusses the possible implications of the hypocretin discovery.

Animals↗

Sleep disorders.

Many pharmacologic and nonpharmacologic strategies are available to treat sleep disorders successfully. Conventional stimulants and the new stimulant modafinil have roles to play in the management of narcolepsy and idiopathic hypersomnia. Knowledge of the properties and clinical effects of these drugs allows adequate doses of medications to be used with the goal of attaining as maximal alertness as possible. A range of dopaminergic agents is available to treat restless legs syndrome; other medications such as opiates, benzodiazepines, and anticonvulsants can also be used. Successful use of the dopaminergic agents depends on an understanding of the phenomena of augmentation, rebound, and tolerance. Arousal parasomnias can be treated with behavioral methods such as hypnosis and drug therapy. Clonazepam provides relief of the symptoms in most patients with REM sleep behavior disorder.

Disorders of Excessive Somnolence↗

Stridor and death in multiple system atrophy.

Patients with multiple system atrophy (MSA) have a mean survival of 8 to 10 years. Nocturnal stridor has been considered a poor prognostic feature. We analyzed demographic, clinical, and polysomnographic data and obtained follow-up information from 42 patients with MSA (30 with follow-up data) seen in a Sleep Disorders Center. Group I consisted of 17 patients with nocturnal stridor, including seven with daytime stridor. Group II consisted of 25 patients without stridor. Analysis of survival curves of 30 patients with follow-up information showed a significantly shorter survival from the sleep evaluation, but not from disease onset, for patients with stridor compared with those without. Nine of 11 patients with stridor died a median of 2 years from presentation and the only two survivors had undergone tracheostomy. Patients with daytime stridor and immobile vocal cords had especially poor prognoses. However, two of four patients with tracheostomies also died, as did six of 19 without stridor. We postulate that central hypoventilation and its complications may have been responsible for many of these other deaths. We conclude that stridor does carry a poor prognosis in patients with MSA but that there are also other causes of death. We recommend consideration of tracheostomy for patients with MSA who have stridor, but also assessment for central hypoventilation and appropriate management if it is present.

Aged↗

Rapid eye movement sleep behaviour disorder: demographic, clinical and laboratory findings in 93 cases.

We describe demographic, clinical, laboratory and aetiological findings in 93 consecutive patients with rapid eye movement (REM) sleep behaviour disorder (RBD), which consists of excessive motor activity during dreaming in association with loss of skeletal muscle atonia of REM sleep. The patients were seen at the Mayo Sleep Disorders Center between January 1, 1991 and July 31, 1995. Eighty-one patients (87%) were male. The mean age of RBD onset was 60.9 years (range 36-84 years) and the mean age at presentation was 64.4 years (37-85 years). Thirty-two per cent of patients had injured themselves and 64% had assaulted their spouses. Subdural haematomas occurred in two patients. Dream content was altered and involved defence of the sleeper against attack in 87%. The frequency of nocturnal events decreased with time in seven untreated patients with neurodegenerative disease. MRI or CT head scans were performed in 56% of patients. Although four scans showed brainstem pathology, all of these patients had apparently unrelated neurodegenerative diseases known to be associated with RBD. Neurological disorders were present in 57% of patients; Parkinson's disease, dementia without parkinsonism and multiple system atrophy accounted for all but 14% of these. RBD developed before parkinsonism in 52% of the patients with Parkinson's disease. Five of the 14 patients with multiple system atrophy were female, and thus the strong male predominance in RBD is less evident in this condition. Psychiatric disorders, drug use or drug withdrawal were rarely causally related to RBD. Clonazepam treatment of RBD was completely or partially successful in 87% of the patients who used the drug. We conclude that RBD is a well-defined condition and that descriptions from different centres are fairly consistent. It is commonest in elderly males and may result in serious morbidity to patients and bed partners. There is a strong relationship to neurodegenerative disease, especially Parkinson's disease, multiple system atrophy and dementia, and neurologists should explore the possibility of RBD in patients with these conditions. RBD symptoms may be the first manifestations of these disorders and careful follow-up is needed. Neuroimaging is unlikely to reveal underlying disorders not suspected clinically. We confirm the effectiveness of clonazepam, but note that attention to the safety of the bed environment may be sufficient for patients with contraindications to the drug.

Adult↗

REM sleep behavior disorder and dementia: cognitive differences when compared with AD.

OBJECTIVE: To determine whether the dementia associated with REM sleep behavior disorder (RBD) differs from Alzheimer's disease (AD) and, if so, whether differences in cognitive performance between RBD/dementia and AD resemble reported differences between dementia with Lewy bodies (DLB) and AD. METHODS: This retrospective study compares neurocognitive performance between 31 patients with degenerative dementia and polysomnography-confirmed RBD and 31 patients without brainstem Lewy body pathology who met Consortium to Establish a Registry for Alzheimer's Disease (CERAD) clinical and neuropathologic criteria for AD. The patient groups did not differ in dementia severity (based on Global Deterioration Scale score) or duration. RESULTS: RBD preceded or coincided with the onset of cognitive decline in 94% of the patients. All but one patient with RBD/dementia had one or more of the following clinical features of DLB: visual hallucinations, extrapyramidal signs, or fluctuating cognition/alertness. The data revealed significantly worse performance on attention, perceptual organization, visual memory, and letter fluency for the RBD/dementia group, whereas the AD group showed significantly worse performance on confrontation naming and verbal memory. CONCLUSIONS: Patients with RBD and degenerative dementia demonstrate a significantly different pattern of cognitive performance from patients with AD. Most of the patients in the RBD/dementia sample also meet criteria for possible or probable DLB, and the pattern of cognitive differences from AD is similar to reported comparisons between DLB and AD. The cognitive and clinical data provide evidence to suggest that the dementia associated with RBD may represent DLB.

Aged↗

REM sleep behavior disorder and degenerative dementia: an association likely reflecting Lewy body disease.

BACKGROUND: REM sleep behavior disorder (RBD) has been reported with various neurodegenerative disorders, most frequently in disorders with Lewy body pathology. RBD often precedes the onset of PD, and a recent prospective study showed that 38% of patients with RBD eventually developed PD. METHODS: We identified 37 patients with degenerative dementia and a history of bursts of vigorous movement of the arms and legs with vocalization during sleep and associated with dream recall. Patients with and without two or more signs of parkinsonism were compared. Clinical, laboratory, and neuropsychometric features were analyzed, and criteria for the clinical diagnosis of dementia with Lewy bodies (DLB) were applied to all patients. RESULTS: Thirty-four of the 37 patients were male with mean age at onset of 61.5 years for RBD and 68.1 years for cognitive decline. RBD commenced before or concurrently with dementia in all patients but two. Parkinsonism (two or more signs) occurred in 54% of the sample (20/37), with a mean age at onset of 69.1 years. Polysomnography (PSG) confirmed RBD in all patients studied. Neuropsychological testing demonstrated impaired perceptual-organizational skills, verbal fluency, and marked constructional dyspraxia in more than one-half the patients. There were no statistically significant differences in the frequency of clinical features or in neuropsychological performance between patients with and without parkinsonism. Thirty-four patients (92%) met criteria for clinically possible or probable DLB. Three patients were autopsied; all had limbic with or without neocortical Lewy bodies. CONCLUSIONS: We report a group of predominantly male patients with a characteristic association of RBD and degenerative dementia. The clinical and neuropsychometric features of the groups of patients with and without parkinsonism are similar. We hypothesize that the underlying pathology in these patients is DLB.

Aged↗

Acute disseminated encephalomyelitis after accidental injection of a hog vaccine: successful treatment with plasmapheresis.

Acute disseminated encephalomyelitis, an inflammatory demyelinating disease of the central nervous system, can occur after viral infections or vaccinations. We report the clinical and neuroimaging findings in a 52-year-old man in whom acute disseminated encephalomyelitis developed after accidental self-injection of an industrial hog vaccine. The protracted and progressive clinical course, despite high-dose parenteral corticosteroid therapy, was altered by aggressive plasmapheresis.

Accidents, Occupational↗

Pergolide in the management of restless legs syndrome: an extended study.

Twenty patients with problematic restless legs syndrome (RLS) were treated with pergolide. Efficacy, dosage, side effects, and tolerance were analyzed. Fifteen patients continued treatment for a median study time of 2 years. Five patients discontinued treatment after a mean of 4.2 months. Pergolide resulted in complete or near complete control of symptoms in 45% and moderate control in 50% of patients studied. Levodopa-induced daytime augmentation resolved in all patients in whom it had been present. The mean total daily maintenance dose of pergolide was 0.23 mg. Forty percent required an additional afternoon dose. Side effects developed in 12 patients (60%) and necessitated discontinuation of treatment in five. Common side effects were nausea, dizziness, and insomnia. Daytime augmentation occurred in 27% of patients, but this was mild and usually easily controlled with a supplementary afternoon dose of pergolide. Tolerance did not develop. We conclude that pergolide is an effective second-line agent for RLS, especially following levodopa-induced daytime augmentation.

Adult↗

Restless legs syndrome.

Restless legs syndrome is a common condition characterized by unpleasant limb sensations that are precipitated by rest and relieved by activity. Symptoms are worse during the evening and may result in insomnia. Most cases are idiopathic, although the condition is sometimes familial and may be associated with a range of medical illnesses, including chronic renal failure and iron deficiency anemia. Restless legs syndrome is responsive to several medications, including levodopa, dopamine agonists, benzodiazepines, opioids, and some anticonvulsants. A practical approach to management involves a stepwise plan, commencing with intermittent therapy with less potent agents for mild cases and progressing to medications with greater potency but a higher potential for side effects.

Diagnosis, Differential↗

Myokymic discharges of the tongue after radiation to the head and neck.

We report two patients who developed myokymic discharges of the tongue after radiation therapy. One patient had carcinoma of the nasopharynx, and the other had a chemodectoma of the middle ear. Radiation therapy may damage the hypoglossal nerve and cause myokymia of the tongue, similar to myokymic discharges associated with brachial plexopathies after radiation therapy.

Aged↗

Carotid artery disease in young adults.

The angiographic and clinical findings in 17 young adults (14-39 years) with stenosis and/or occlusion of at least one of the common or internal carotid arteries were reviewed to determine the spectrum of carotid artery disease in this age group. Five aetiological groups were identified: atherosclerosis (3 patients), arteritis (4), non-inflammatory arteriopathies (6), compression by neoplasm (1), and occlusions of undetermined cause (3). Over a mean follow-up time of 19.7 months, 2 patients died (12.5%) and further cerebrovascular events occurred in 4 others (25%). We conclude that carotid angiography plays a meaningful role in providing a definitive diagnosis in young adults with carotid artery disease and thus may assist with therapy and prognosis.

Adolescent↗