A review of published reports on conventional and unconventional viruses, aluminum, neurotoxic metals and trace elements, neurotoxins of biological origin and immune systems, suggest that environmental factors, possibly multiple ones, play a significant role in the etiology of Alzheimer's disease. A complex interaction between genetic predisposition to this illness, natural aging processes, environmental factors over a life-time exposure and pathological alterations of the host immune system is proposed.

Brain death and the persistent vegetative state (PVS) share the following features: 1.) There is death of neurons in the brain; 2.) Both require an etiology which is capable of causing neuronal death. 3.) The potential for cognition is totally and permanently lost; 4.) Intensive medical support is usually withdrawn. In contrast, the diagnosis of brain death depends on death of the brainstem, while PVS implies permanent and total loss of forebrain function. While brainstem death can be diagnosed clinically, accurate prognosis in PVS requires additional investigation. Thus far, the EEG is the most specific test of neuronal function in the cerebral cortex. Brain death is equivalent to death, while PVS is not; management of the latter is more complex because of medical, social, ethical and legal factors.

Fourteen patients with intractable epilepsy underwent surgical resection of their epileptogenic focus. Hippocampal and temporal cortical samples were obtained, and subjected to high performance liquid chromatography with electrochemical detection. Levels of 5-hydroxyindoleacetic acid (5-HIAA) in actively spiking temporal cortex were 0.454 ± 0.012 ng/mg (mean ± SEM), contrasting with less actively spiking cortex values of 0.248 ± 0.042 ng/mg and normal literature values, obtained from post-mortem material, of 0.140 ± 0.050 ng/mg. Similarly, homovanillic acid (NVA) levels were significantly increased in epileptic tissue compared to normal literature values. Actively spiking cortex values were 0.172 ± 0.001 pg/mg, less active cortex values were 0.058 ±0.012 pg/mg, and literature values were 0.011 ± 0.002 pg/mg. Although a direct statistical comparison between the data reported here and literature values may not be valid, the findings show a continuum from normal through increasingly active electrode sites, likely reflecting a true biologic phenomena. Similarly, statistically significant increases in 5-HIAA and HVA levels were found in hippocampal tissue, which also showed significantly lower dihydroxyphenylacetic acid levels. We conclude that raised levels of serotonin and dopamine metabolites in actively spiking cortex likely reflect an increase in their turnover, and are an epileptic epiphenomenon. Exaggeration of turnover may represent the “metabolic noise” of epilepsy, rather than a concerted strategy of local or distal neurons to contain an epileptogenic focus.

Temporal interictal rhythmic delta activity or TIRDA was found in 45 of the 127 recordings of patients with complex partial epilepsy (CPE) referred for both awake and sleep EEC TIRDA was more abundant during drowsiness and light sleep; it occurred more characteristically as trains of 50-100 µv sinusoidal or saw-toothed l-4Hz activity, recorded predominantly from anterior temporal regions. When occurring bilaterally and independently, TIRDA varied from side to side. TIRDA is often found in association with anterior temporal spikes or sharp waves (TS) particularly during sleep, as observed in 43 out of 45 EEGs. TIRDA can nevertheless occur as an isolated abnormality, as noted in two sleep and 12 awake study recordings. Because of its high specificity and positive predictive value over a large range of prevalence, TIRDA should be singled out as an accurate interictal indicator of CPE. In patients with isolated TIRDA, the cost of prolonged EEG recording during sleep for the purpose of activating TS has to be weighed against the yield of eventually confirming the obvious.

On three adjacent kibbutzim (collective rural communities) in the Negev (Southern Israel) 13 parkinsonian patients were found among a population of 592 persons 40 years or older. The clinical picture was not different from that of patients from other areas with idiopathic parkinsonism. Long term residence in the kibbutzim is characteristic of this population. In the past most of the drinking water has been supplied by wells from a common aquifer. From other patients with Parkinson's disease in the Negev, we estimated the age-specific incidence for the region. The incidence is about five times greater in each of these kibbutzim than in the remainder of the Negev. Although associations with rural residence and well water use have been reported elsewhere, clusters of this sort have not been reported. They strongly suggest that a common environmental factor exists.

Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) activities of lumbar cerebrospinal fluid (CSF) have been measured in seventeen patients with a clinical diagnosis of probable Alzheimer's disease (Prob AD), possible Alzheimer's disease (Poss AD), or dementia of non-Alzheimer aetiology (Non-AD). The three diagnostic groups did not differ with regard to the Km or saturation kinetic properties of AChE and BChE. The CSF AChE activity was significantly higher in Prob AD than in Non-AD patients. The groups did not differ significantly in BChE activity. The ratio of AChE to BChE activity was significantly higher in both the Prob AD and Poss AD groups than in the Non-AD group, and the ranges of values in the Prob AD and Non-AD groups did not overlap. Among patients in the Prob AD group, severity of dementia was correlated with both AChE activity and the AChE/BChE ratio, and progression of dementia over time was also correlated with AChE/BChE.

The AChE/BChE ratio correlated more strongly than AChE with severity and progression of dementia in Prob AD patients, and also better distinguished them from Non-AD patients, suggesting that AChE/BChE may be the more useful marker for diagnosis of AD. It is not clear from the results whether AChE/BChE is useful for diagnosis of the complex dementia cases in the Poss AD group.

Fifty patients with ruptured intracranial aneurysms and 8 patients with elective clipping of unruptured aneurysms had daily transcranial Doppler (TCD) measurements performed. The highest mean middle cerebral artery velocity (MCA-Vel) was considered to be the best single parameter forjudging a patient's susceptibility to clinically significant vasospasm (VSP). Surgery for the clipping of unruptured aneurysms by itself does not lead to an increase in MCA-Vel. There is a progressive increase in MCA-Vel after subarachnoid hemorrhage (SAH) from aneurysms which peaks between 7 and 10 days. The MCA-Vel is higher on the side of the ruptured aneurysm and the degree of rise is greater if blood is seen on the initial CT scan. It is highly unlikely that a patient whose MCA-Vel remains under 100 cm/sec has a degree of angiographic VSP which causes clinical symptomatology. Patients whose MCA-Vel is > 200 cm/sec are at great risk of developing clinical symptomatology of VSP and are very likely to have significant angiographic VSP. There is a transitional zone in between these two levels.

Two cases of deep cerebral venous thrombosis are presented with specific reference to the CT and MR findings. The MR findings are discussed, with comparison to the findings of superficial cerebral sino-venous occlusion.

Central nervous system toxoplasmosis is a well known disease of immunocompromised patients. Neuropathologic examinations have only rarely demonstrated spinal cord involvement. This report describes a fatal case of toxoplasmosis that presented with a subacute myelopathy. Toxoplasmosis should be considered in immunocompromised patients, including patients with the acquired immune deficiency syndrome, that develop intramedullary lesions of the spinal cord.

We report three siblings, offspring of normal consanguineous parents, with a progressive neurological illness that began in midlife and was characterized primarily by chorea and leading to death in the fourth decade. The proband had erythrocyte acanthocytosis with normal serum β-lipoprotein. Biopsy of left gastrocnemius muscle showed neurogenic muscular atrophy. There was a decrease in the numbers of large myelinated axons of the sural nerve. Postmortem examination of two cases showed marked atrophy, neuronal loss and gliosis of the caudate nucleus and putamen. Autosomal recessive inheritance is likely in this family.

Hospital records of thirty patients with methanol poisoning were studied. Neurologic manifestations at presentation including coma, seizures and decreased visual acuity were seen in nineteen patients. The mean blood pH at presentation was significantly lower in the patients with these neurologic signs and symptoms than in the eleven patients without them (p < 0.05). Methanol levels at presentation tended to be higher in patients with neurologic manifestations at presentation and these patients tended to present later after methanol ingestion than those patients without neurologic manifestations. Fifteen patients with methanol poisoning developed serious neurologic sequelae or died. The mean blood pH was significantly lower in this patient group than in those who survived without neurologic sequelae (p < 0.05). Methanol levels at presentation were not different in the patients who developed neurologic sequelae or died as compared to those who did not. The time from ingestion of methanol to presentation at the hospital was however significantly longer in those patients who developed neurologic sequelae or died (p < 0.05). Initiation of treatment within eight hours of ingestion of methanol was associated with a better clinical outcome.

A 68-year-old man known to have inclusion body myositis underwent a cricopharyngeal myotomy in an attempt to improve his progressive dysphagia. Morphological studies from tissues obtained during this procedure showed the diagnostic features typical of this chronic inflammatory myopathy. To our knowledge this is the first pathological demonstration of inclusion body myositis involving the pharyngeal skeletal musculature.

Although pain is not generally recognized as a symptom of tic disorders, we have seen a number of patients in whom this was a prominent feature, at times even the symptom of greatest concern. The commonest pain complaints are those arising from the actual performance of a tic. Most often this follows directly from the discomfort produced by sudden or repeated extreme exertion. Here the origin of the pain is usually musculoskeletal, though rare examples of neuropathic pain may occur. Pain also may arise from striking or being struck by a moving body part involved in large amplitude tics. Other related painful acts include deliberate self-injury and pain inflicted upon others. A second major category is represented by a smaller number of patients who complain of pain during voluntary efforts to suppress their tics. Finally, there are patients who obtain relief from tics while experiencing pain, to such an extent that they will deliberately provoke pain to obtain its benefit. We feel that pain should be recognized as a common complaint, and occasionally a source of significant disability, in patients with tics.

We studied a 42-year-old woman who had persistent active acromegaly despite conventional therapies. She was treated for 6 months with SMS 201-995. Her mean plasma growth hormone GH values decreased during treatment from 9.1 ± 1.2 to 6.6 ± 1.2 µg/L. One month after the withdrawal of SMS 201-995, the plasma GH level increased to 24.4 µg/L (P < 0.001). This elevation was clinically silent and transitory, as GH levels decreased 8 months later to 6.9 ± 1.3 µg/L. Furthermore, at the beginning of therapy, her intractable headache was completely relieved; however, it progressively resumed under therapy. In conclusion, cessation of SMS 201-995 may be followed in some acromegalic patients by a rebound of plasma GH levels. This rebound suggests that SMS 201-995 decreases GH levels by an inhibition of its release from the pituitary. Furthermore, SMS 201-995 may relieve intractable headache in some acromegalic patients, but tolerance to the analgesic effect may develop.

Seven French-Canadian cases of clearcut oculopharyngeal muscular dystrophy (OPMD) had their muscle studied for the presence of intranuclear inclusions, and they were all positive. Inclusions of both “mature” and “immature” types were seen in our material. The presence of such intranuclear structures should be added to the criteria of the clinical picture and the family history for diagnosis of a case and inclusion of a family in further genetic studies. Reverse genetic studies of large families and biochemical studies of these intranuclear structures may help to understand the pathogenesis of this common disease in Quebec.