Pulmonary embolism: an under-recognized yet frequent cause of death in parkinsonism

There are very few detailed reports on the cause of death in patients with Parkinson syndrome, and most reports lack postmortem verification. Pulmonary embolism has been reported as an infrequent terminal event. We reviewed the results of 60 complete autopsies performed on patients with Parkinson syndrome personally cared for at our institution. Pulmonary embolism was second only to pneumonia as the most common cause of death overall.

Dopa-responsive dystonia: pathological and biochemical observations in a case

We report the first neuropathological and neurochemical study of a patient with dopa-responsive dystonia. She had onset of foot dystonia at age 5 years and by age 8 years it was generalized with prominent right leg and arm involvement. On levodopa 750 mg daily she had complete symptomatic improvement that was sustained for 11 years until death. Pathological studies revealed normal numbers of hypopigmented substantia nigra neurons, normal tyrosine hydroxylase (TH) immunoreactivity and TH protein in the SN, no inclusion bodies or gliosis, and no evidence of a degenerative process in the striatum. Biochemical studies revealed reduced dopamine in the substantia nigra and striatum (8% in the putamen and 18% of control in the caudate) with a similar but not identical subregional distribution as in idiopathic Parkinson's disease. In the striatum, TH protein and TH activity was reduced, with the loss more pronounced in the putamen than the caudate. The GBR 12935 binding to DA transporter was normal in the caudate and at the lower end of the range of control values in the putamen. We conclude that disturbed dopamine synthetic capacity or a reduced arborization of striatal dopamine terminals may be the major disturbance in dopa-responsive dystonia.

Prevalence of movement disorders in elderly community residents

We studied movement disorders (MD) in community residents of Saskatchewan aged > or = 65 years. A representative sample of 70 individuals had detailed neurological evaluation. Those who had definite and possible MD at first examination had a second neurological assessment by a senior neurologist. The most prevalent MD was essential tremor (ET) (14%) followed by Parkinson's disease (PD) (3%). The marked difference in prevalence ratios for PD and ET are attributed to: (a) higher incidence of ET in the general population; (b) a greater possibility that most, if not all, ET cases would reside in the community whereas a sizable proportion of elderly PD cases may be institutionalized, and (c) shortened survival in PD but a normal life expectancy in ET.

Alzheimer's disease and idiopathic Parkinson's disease coexistence

Idiopathic Parkinson's disease (IPD) and Alzheimer's disease (AD) are common neurologic diseases of old age. Parkinson syndrome is easy to recognize even at an early stage, but identifying early AD is often difficult. Accurate clinical diagnosis is important for assigning the prognosis and for studies aimed at assessing the efforts to slow down progression of these diseases. During 22 years, we identified six patients who had clinical features of parkinsonism and dementia and who at autopsy had both IDP and AD and 20 parkinsonian patients without dementia who at autopsy had only IPD. The clinical profile in these two groups was compared. The onset of Parkinson syndrome in the patients with dual pathology had a bimodal distribution--before or after age 65 years. In the three cases with onset before age 65 years, there was sequential evolution of IPD and AD. In contrast, those older than 65 years at onset manifested the clinical features of both IPD and AD simultaneously. The mode of onset and the dominant parkinsonian features in the three patients with sequential clinical evolution were similar to those seen in the nondemented IPD cases; however, lack of self-confidence and inability to make decisions resulted in considerably greater functional disability than could be accounted for by parkinsonism alone. These characteristics may be helpful in early recognition of dual IPD and AD pathology. Psychiatric side effects of levodopa therapy were more common in those with dual pathology than in those with IPD alone.

Significance of parkinsonian manifestations in essential tremor

Parkinsonian features, notably resting tremor may be seen in some essential tremor patients but the significance of those is unknown. The reported risk of parkinsonism in essential tremor patients varies from being unchanged to 35 times higher than expected. We studied 9 patients with essential tremor who had autopsies. In 6 of the 9 (66%) resting tremor was noted and in 3 (33%) cases fully developed parkinsonism was noted. The parkinsonism was consequent to neuroleptic usage in 2 and to basal ganglia status lacunaris and cribrosus in one case but no consistent abnormalities were noted in 3 essential tremor only and 3 essential tremor plus resting tremor cases. We conclude that resting tremor is an age-related natural evolution in some essential tremor patients. We recommend that the additional diagnosis of parkinsonism in the essential tremor be made only when resting tremor, bradykinesia and rigidity are all evident. The risk of ideopathic Parkinson's disease in essential tremor cases is similar to the general population.

Prognostic significance of the onset mode in parkinsonism

Early recognition of the prognosis in parkinsonism is important for both the management and studies aimed at preventing progression of disease. Less favorable prognosis is reported in early-onset postural instability and gait difficulty (PIGD) than in the tremor-onset cases, but the reasons for this are unknown. In 70 autopsy-verified cases, 11 (15.7%) had PIGD, and 34 (49%) had tremor onset. Improvement on levodopa was more common in the tremor-than the PIGD-onset cases (p < 0.05). The majority of tremor-onset cases had Lewy body disease, while the majority of PIGD-onset cases had other forms of pathology. Survival was shorter in the PIGD- than the tremor-onset cases (p < 0.05).

Oxygen free radical producing activity of polymorphonuclear leukocytes in patients with Parkinson's disease

Oxygen free radicals (OFRs) have been suggested in the pathogenesis of Parkinson's disease (PD). These free radicals exert their cytotoxic effect by peroxidation of lipid membrane resulting in the formation of malondialdehyde (MDA). Polymorphonuclear (PMN) leukocyte is one of the major sources of OFR. However, the oxygen free radical producing activity of PMN leukocytes in patients with PD is not known. We therefore studied the oxygen free radical producing activity of polymorphonuclear leukocytes and MDA levels in the serum of healthy subjects and in patients with Parkinson's disease. The oxygen free radical producing activity of PMN leukocytes in blood and the MDA content in serum were significantly higher in patients with Parkinson's disease than in healthy subjects. These results indicate a possible role of oxygen free radicals in the pathogenesis of Parkinson's disease.

Serum antioxidant enzyme activity in Parkinson's disease

The activities of superoxide dismutase (SOD; EC 1.15.1.1) and glutathione peroxidase (GSHPx; EC 1.11.1.9), the enzymes that metabolize the superoxide anion and hydrogen peroxide, respectively, were measured in serum from healthy subjects and patients with Parkinson's disease (PD). The activities of SOD and GSHPx in patients with PD were higher than those in normal healthy individuals. These results suggest that the increased activities of these enzymes could be due to oxidative stress in the initial stages of this disease.

Frequency and cause of Parkinson's disease

Parkinson syndrome (PS) is a common disorder in the North American population. The annual incidence rate is 20.5/100,000 population and the mean survival after onset is approximately 12.3 years. The estimated prevalence rate is about 300/100,000 population. The incidence and prevalence rates rise with advancing age. Both the widespread use of levodopa and the improved health care in general have increased the longevity in PS. The survival in PS from the time of the first clinic visit is still significantly shorter when compared with the regional age and sex matched population. The cause of IPD may be related to some environmental factor(s)--most likely a toxin. Genetic factors are not the cause but in some families, may predispose to IPD.

Clinicopathologic observations in essential tremor: report of six cases

Essential tremor (ET) is the most common pathologic tremor, but only eight cases have been studied pathologically. We report detailed clinical and neuropathologic studies of six additional patients. We did not find any neuropathologic lesions that might be specific for ET. Moreover, there were no abnormalities of the substantia nigra consistent with Parkinson's disease. The neuropathologic substrate of ET remains unknown.

Occurrence of resting tremor in Parkinson's disease

Several previous studies have noted that resting tremor (RT) is absent in 10% to 30% of idiopathic Parkinson's disease (IPD) patients. We report our 22-year observations in 47 pathologically verified parkinsonian patients. In all the IPD cases with median follow-up of 3.7 years, RT was noted on at least one evaluation. Among other parkinsonian syndrome variants characterized by widespread subcortical pathology with median follow-up of 2.86 years, RT was seen in 31% of the cases. Our data indicate that the sites typically involved in IPD are sufficient to produce RT.

Accuracy of clinical diagnosis in parkinsonism--a prospective study

Clinical diagnosis of Parkinson's syndrome (PS) is reasonably easy in most cases but the distinction between different variants of PS may be difficult in early cases. The correct diagnosis is not only important for counselling and management of patients but also in conducting pharmacological and epidemiological studies. There is very little critical literature on the pathological verification of the clinical diagnosis in PS. We report our 22 years experience to address that issue. Between 1968 and 1990, 65 PS patients came to autopsy. Complete data are available in 59 (M-50, F-19) cases. The initial diagnosis made by a qualified neurologist was idiopathic Parkinson's disease (IPD) in 43 cases. Of those 28 (65%) had Lewy body pathology. After a mean duration of 12 years the final diagnosis was IPD in 41 cases which was confirmed in 31 (76%). The IPD could not be clinically distinguished from cases with severe substantia nigra neuronal loss without inclusions or from those with neurofibrillary tangle inclusions and neuronal loss at the anatomical sites typically involved in IPD. All progressive supra-nuclear palsy, olivopontocerebellar atrophy, Jakob-Creutzfeldt's disease and the majority of the multiple system atrophy cases were diagnosed correctly during life. The correct clinical diagnosis in most non-IPD variants of PS was possible within 5 years of onset (range: 2 months to 18 years). We recommend that studies aimed at including only the IPD cases restrict the enrollment to those cases that have had PS motor manifestations for five years or longer duration.

National conference on Parkinson's disease

A National Conference on Parkinson's disease was held on September 7th-8th, 1990 in Victoria, British Columbia. The scientific program included 11 formal presentations, 10 small group workshops and video presentations of interesting examples of movement disorders. The subjects discussed ranged from epidemiology and etiology to current and possible future modes of management of Parkinson's disease.

Levodopa efficacy and pathological basis of Parkinson syndrome

Levodopa is the most effective drug for symptomatic control of Parkinson syndrome (PS). We report a 22-year clinicopathological study of 59 PS cases. Of the entire group, 37 (63%) had an adequate trial on levodopa. Some improvement was noted on that drug in 24 (65%) cases. Improvement was seen in 94% of idiopathic Parkinson's disease cases as well as in all cases in which the pathology was characterized by neuronal loss in the substantia nigra without Lewy body inclusions. Improvement was also noted in 60% of patients with the dual pathology of idiopathic Parkinson's disease and Alzheimer's disease, and in one-third of early multiple system atrophy cases. We conclude that improvement on levodopa is a strong indication that the pathological basis of the parkinsonism is the damage to substantia nigra neurons. A favorable response to levodopa, however, is not an indication of idiopathic (Lewy body) Parkinson's disease.

Use and abuse of drugs in the elderly

1. Study of 100 patients admitted to the Geriatric Assessment Unit, to evaluate the appropriateness of drug therapy in the elderly. 2. Average patient took 5.15 drugs at admission and 3.67 drugs at discharge. 3. Inaccurate dosages found in 14%, drug-drug interaction in 31%, drug contraindications were evident in 23% and at least one unnecessary drug was prescribed in 39% patients at admission. 4. At discharge, 8% cases had potential drug-drug interaction and 2% received unnecessary drugs.

Hypersexuality with antiparkinsonian therapy

Thirteen parkinsonian patients drawn from two large parkinsonism clinics experienced hypersexuality as a consequence of anti-parkinsonian therapy. The cases include only those whose sexual behavior on treatment became a concern to the patient's family or a social agency. The majority of patients were men and had a relatively early onset of parkinsonian symptomatology. There was no relation between functional improvement and increased sexuality. Most patients showed some element of dose dependency between antiparkinsonian drugs and the hypersexual behavior. Prior sexual profile included from no sexual outlet to hypersexuality. Neither the prior history of psychiatric illness nor brain damage predisposed to such response on treatment, and in most patients, it was not a part of hypomania or a more diffuse psychiatric disturbance. We propose that hypersexuality on antiparkinsonian drugs is consequent to inhibition of prolactin secretion.

Regional metal concentrations in Parkinson's disease, other chronic neurological diseases, and control brains

Metal deficiency or toxicity states have been recognized as a cause of several neurological disorders and are suspected in others. We analyzed four brain regions (frontal cortex, caudate nucleus, substantia nigra, and cerebellum) in 36 human brains for concentrations of 24 metals (Ag, Al, As, B, Be, Ca, Cd, Co, Cr, Cu, Fe, K, Pb, Mg, Mn, Mo, Na, Ni, P, Se, Ti, V, W, Zn). Regional metal concentrations, measured using atomic absorption and atomic emission spectroscopy, were compared between 9 Parkinson's disease (PD) brains, 15 brains from patients with other chronic neurological diseases, and 12 control brains. No significant metal concentration differences were noted between brains from PD and other chronic neurologic disease. However, parkinsonian brains (PD and parkinsonism secondary to neurofibrillary tangle disease) showed lower concentrations of magnesium in the caudate nucleus and copper in the substantia nigra than control brains. These findings may represent an etiologically important clue to parkinsonism.

Recurrent spinal cord ischemia due to abdominal aortic aneurysm--a case report

Ischemic spinal cord lesions with abdominal aortic aneurysm are rare and are usually characterized by a single catastrophic event. The authors report a seventy-five-year-old woman who, over a period of three years, had three attacks of acute neurologic deficit. The clinical features were those of bladder incontinence, a mixture of upper and lower motor neuron lower limb motor deficit, and patchy sensory loss with a sensory level at T10-12. Investigations revealed a large abdominal aortic aneurysm that had enlarged with time. This case, they believe, represents an example of recurrent ischemic myelopathy due to occlusion at the mouth of radicular arteries or recurrent embolic events in those vessels.

Parkinsonism and neurofibrillary tangle pathology in pigmented nuclei

Four parkinsonian patients had neurofibrillary tangles, neuronal loss, and gliosis restricted to the substantia nigra and locus ceruleus. No Lewy body inclusions or other neuropathological changes accounting for parkinsonism were found in any of these patients. Their clinical features were characterized by an early age of onset, absence of dementia, absence of other neurological abnormalities, good response to drug therapy, and a long, slowly progressive course of illness. None of the patients had any history of encephalitis. These patients either represent a forme fruste of postencephalitic parkinsonism or a new entity thus far not described.

Neurological disorders and services in Saskatchewan--a report based on provincial health care records

A study of neurological disorders and services is presented. The ten most common neurological diagnoses were headache, back disorders, neuropathy, cerebrovascular disease, dizziness/insomnia, myopathies, soft tissue disorder, intracranial injury, neurological symptoms (numbness, etc.), and Parkinson's disease. The pattern of diseases is similar to that reflected in the prevalence of those in the US. The annual beneficiary rate was 1.6% of the population, the median age was 45 years, and the majority (52%) served were females. There were 1.8 annual services per beneficiary and the median hospital stay was 9 days. Ambulatory care accounted for the majority (62%) of services and 64% of the inpatient services were delivered by neurosurgeons. The majority of the admissions (61%) and of the ambulatory services (55%) were provided in Regina.

Geography, drinking water chemistry, pesticides and herbicides and the etiology of Parkinson's disease

In 1984 we made the first observation of a correlation between early age exposure to rural environment (and drinking well water) and development of idiopathic Parkinson's disease (IPD). These findings were subsequently confirmed elsewhere (Barbeau, 1985;25 Tanner, 1985). Analysis of all early age onset IPD (EPD) cases born and raised in Saskatchewan revealed that 20 of 22 had exclusively rural exposure during the first 15 years of life. This distribution was significantly different from the general population (p = 0.0141). Further study of the EPD group included sampling and metal analysis of childhood sources of drinking water in 18 cases and 36 age and sex-matched controls. Water collected from the two groups was analyzed for 23 metals (including 7 elements implicated in the etiology of IPD). There was no difference in the metal composition of the water between the two groups. Finally, a review of herbicide and pesticide use in Saskatchewan agriculture was undertaken to determine if there was an increased incidence of EPD following utilization of any particular chemical. No increase was found in the incidence of EPD with the introduction of any pesticide or herbicide, including Paraquat, for agricultural use. We conclude that there is a strong correlation between early age rural environmental exposure and development of IPD. We believe well water is a likely vehicle for the causal agent, but neither water metal concentration nor any of the herbicides and pesticides used in Saskatchewan agriculture are related to the cause.

A case-control study of smoking habits, dementia, and other illnesses in idiopathic Parkinson's disease

From 1967 to 1979, 118 incident cases of idiopathic Parkinson's disease (IPD) and 236 age- and sex-matched controls from Rochester, MN, were identified. Medical records on patients and controls for 40 years preceding the diagnosis of IPD were reviewed. The relative risk (RR) for ever-smoked and IPD was not significantly different from unity (RR = 0.7, 95% confidence interval = 0.4 to 1.2). The mean age at diagnosis of IPD was significantly younger (p = 0.007) in the ever-smokers (68.8 years) compared with never-smokers (73.8 years), although this needs to be interpreted cautiously. It is concluded that smoking had no effect on the development of IPD. Within 5 years after the index date, a new diagnosis of dementia was made more often in cases than in controls (p = 0.01). Relative risk of IPD significantly increased when prior diagnosis of psychoneurosis and psychosomatic illness had been made.

Regional distribution of metals in human brain

Progress in understanding the role of metals in diseases of the nervous system has been hampered to a large extent by a lack of normal metal concentration values in the human brain. Since several metals interact metabolically, concurrent metal levels are essential for clinical correlation. We are reporting a simultaneous analysis of 24 metals in 4 different areas of 9 human brains. Our data on previously studied metals are comparable to the past observations. Therefore, we suggest the values of all metals reported here should be regarded as "normal" for ages 58-78 years.

Early onset Parkinson's disease in Saskatchewan--environmental considerations for etiology

The cause of idiopathic Parkinson's Disease (PD) is not known but it is believed to be related to some environmental agent(s). Given a long preclinical interval and onset of symptomatology around age 60 years, it becomes impossible to identify and analyze all prior environmental factors satisfactorily. To circumvent these difficulties we evaluated the childhood environment in those PD patients whose symptoms began at age 40 years or earlier. Twenty-one such cases were born and raised in the province of Saskatchewan. Nineteen of these 21 patients spent the first 15 years of life exclusively in rural Saskatchewan. Detailed population analysis indicates a strong predisposition to early onset idiopathic Parkinson's Disease (EPD) in those raised in rural areas (p = 0.0154). All but one case utilized exclusively well water for the first 15 years of life--a trait significantly different from that expected in the provincial population. It is concluded that rural Saskatchewan environments contribute to EPD and that well water used in childhood should be considered as a potential vehicle for the etiological agent.

Multiple sclerosis presenting as isolated oculomotor nerve palsy

A 23-year old woman came to the emergency room with an isolated oculomotor nerve palsy (including pupillary dilatation) of rapid onset. Investigations and history revealed no cause. The subsequent course of events indicated a diagnosis of multiple sclerosis. While the third nerve has been shown to be involved during the course of multiple sclerosis, this is the first report of a case presenting as an isolated oculomotor nerve paralysis.

Cyanide-induced parkinsonism: a clinicopathologic report

An 18-year-old man ingested 975 to 1,300 mg of potassium cyanide in a suicide attempt. He was treated and survived the poisoning episode, but then had severe parkinsonian syndrome, characterized primarily by akinesia and rigidity. He died 19 months after the drug overdose. At autopsy, major destructive changes were found in the globus pallidus and putamen, whereas the melanin-containing zone of substantia nigra was intact. This is the first clinicopathologic report of parkinsonism as a result of cyanide poisoning.

Parkinsonism as a manifestation of brain tumor

Neoplasm is an uncommon cause of the parkinsonian syndrome. We are presenting three cases of intracranial tumors whose major manifestations included parkinsonism. Surgical treatment resulted in control of the extrapyramidal symptoms in two of our patients. Because no curative treatment is available for the vast majority of parkinsonian patients, early detection of an underlying neoplasm may offer a most rewarding outcome. Unilaterality of the symptoms, overwhelming dementia, or suspicion of a mass should lead to the performance of computed tomography.

Epidemiology of parkinsonism: incidence, classification, and mortality

An epidemiological study of parkinsonism over a 13-year period (1967 through 1979) is presented, updating previous reports on incidence and trend in the population of Rochester, Minnesota. The overall average annual incidence of parkinsonism per 100,000 population was 20.5, adjusted to the 1970 total United States population, which is virtually unchanged from previous observations. Incidences calculated for each calendar year (1967 through 1979) revealed no remarkable change following the 1976 swine flu vaccination program. There was no sex difference and the peak incidence occurred between ages 75 and 84 years. Idiopathic Parkinson's disease was the most common variant (86%), followed by drug-induced parkinsonism (7%). There were no new cases of postencephalitic parkinsonism diagnosed during the study period. Relative frequency of other types of Parkinson's disease as identified by practicing neurologists is presented. For each case two age- and sex-matched controls were selected from the Rochester population. The survival rates in the controls were comparable to the general population of the west north central region of the United States. The mortalities in the patients were significantly higher (p = 0.001) than the controls and were unchanged from previous rates reported from the same community. In the 69 (50%) patients treated with levodopa, the mortality was comparable to that in controls. The favorable outcome in these cases is attributed to bias resulting from selection of healthier patients for treatment.

Chronic low-dose levodopa therapy in Parkinson's disease: An argument for delaying levodopa therapy

Levodopa is the most useful drug for treatment of Parkinson's disease today. But after continued use for several years, the effectiveness declines, and the undesirable side effects become more frequent, leading to unsatisfactory control. Once the treatment failure emerges, further management is difficult and often unsuccessful. One alternative for preventing side effects and treatment failure is to use a low dose. We are reporting our 12-year experience on uninterrupted treatment with levodopa, 3 grams (approximate) daily. The improvement was comparable with the best reports on higher dosage, and the side effects were significantly less frequent. The frequency of dyskinesia and on-off phenomena showed a strong correlation with duration of treatment. Psychiatric side effects were more common on treatment, but frequency of dementia did not correlate with duration of therapy. Improvement reached a peak after 6 months and remained statistically significant for 3.5 years. By the end of 5 years, the disability profile in the group was similar to that prior to levodopa treatment. So far, there is no satisfactory method for preventing treatment failure. From our observations, low dosage of levodopa is a desirable alternative, but not the answer to therapeutic failure. We recommend that levodopa use be delayed until the patient has a functional and/or psychological handicap that cannot be satisfactorily controlled with less potent antiparkinsonian agents.

Cerebellar norepinephrine in patients with Parkinson's disease and control subjects

Norepinephrine was measured in postmortem cerebellar cortex of 22 non-neurological control subjects and nine patients with Parkinson's disease, using the high-performance liquid chromatography method with amperometric detection. In all control subjects, substantial amounts of norepinephrine was found in cerebellar cortex. There was a moderate negative correlation between age of control subjects and cerebellar norepinephrine concentration. In the patients with Parkinson's disease, the cerebellar cortical norepinephrine levels were significantly below normal. This is in accord with previously reported reduced norepinephrine levels in locus ceruleus and other regions of the parkinsonian brain. Although the main symptoms of Parkinson's disease are primarily caused by disturbed basal ganglia (dopamine) function, cerebellar dysfunction related to norepinephrine may contribute to some abnormalities of motor performance in this disorder.

Essential tremor in Rochester, Minnesota: a 45-year study

A 45-year (1935-79) retrospective study of essential tremor based on original medical records on residents of Rochester, Minnesota, is presented. The age and sex adjusted incidence for the most recent 15 year period was 23.7 per 100 000 for US white population. The prevalence rate, age and sex adjusted to 1970 US white population on January 1, 1979 was estimated at 305.6 per 100 000. Survival after diagnosis of essential tremor is comparable to age and sex matched population of West North Central United States. Mean age at diagnosis was 58 (range 2-96) years. Age adjusted annual incidence rate was not different in males (18.3/100 000) and females (17.1/100 000). Functional handicap was reported by four (1.5%) of the 266 incidence cases in school, 13 (5%) cases at work and five cases (2%) retired prematurely. Excessive use of alcohol was noted in 16% and 6% were diagnosed as alcoholic. Torticollis was diagnosed in 3% cases and an additional diagnosis of Parkinson's disease after the index date was made in 2% of incidence cases. Subsequent emergence of Parkinsonism was regarded as incidental. Diagnosis of hypertension was made at some time in 30% of incidence cases during the period (mean 37 years) for which the medical records were available. Risk of hypertension after onset of essential tremor in the cases was not different from that in a control group.

Epidemiology of Parkinson's disease

Epidemiology of parkinsonism for 13 years (1967 to 1979) in Rochester, Minnesota is evaluated. For each patient, two age- and sex-matched controls with comparable medical follow-up (mean 40 years before diagnosis) were selected from the same community. Smoking habits, dementia, acute and chronic illnesses and mortality patterns in the two groups are compared. The annual incidence rate was 20.5/100,000, which is virtually unchanged from previous reports on Rochester population. Cigarette smoking habits of cases and the controls before the index date were not significantly different. Prior to diagnosis of Parkinson's disease, dementia was diagnosed significantly more frequently among the patients than the controls (P = 0.048). After diagnosis of parkinsonism dementia emerged nearly three times more frequently in patients than among the controls. Mortality rate in the entire parkinsonian population was similar to that reported from the same community between 1935 and 1966. Only 50% of the patients were treated with levodopa. Among those treated with levodopa the mortality rate was comparable to their controls. Because there were no definite criteria for administering levodopa therapy, higher frequency of dementia and prolonged survival in those treated with this drug could be attributed to the bias of case selection for treatment.

Amantadine-dyazide interaction

To document an interaction between amantadine hydrochloride and Dyazide that had apparently produced amantadine toxicity, a patient was given amantadine alone for 1 week, followed by amantadine plus Dyazide for another week, under controlled conditions. A diuretic effect was observed after Dyazide was added to the regimen, but the urine amantadine excretion fell, and the drug's plasma concentration increased. It was concluded that one or both of the components of Dyazide (hydrochlorothiazide and triamterene) reduce the clearance of amantadine and can produce higher plasma concentrations and toxic effects.

Reversible drug-induced parkinsonism. Clinicopathologic study of two cases

Parkinsonism developed in two patients who were received neuroleptic drugs. In each case the clinical manifestations remitted completely when the offending drug or drugs were discontinued. Histologic examination in each patient disclosed abnormalities characteristic of idiopathic paralysis agitans (IPA). Levels of homovanillic acid were low in both cases, and dopamine (DA) levels were measurably reduced in the striatum in one case. It is postulated that before administration of neuroleptic drugs, both patients had preclinical IPA, which predisposed them to parkinsonism when challenged with DA antagonists. Our observations suggest that some patients with irreversible drug-induced parkinsonism may suffer from IPA and that the reversibility of clinical features does not exclude the presence of subclinical IPA.

Dysautonomia in Parkinsonism: a clinicopathological study

Necropsy studies were done on six patients with idiopathic paralysis agitans, one with multiple system atrophy including features of Parkinsonism, and one control. Autonomic functions had been evaluated during life to a varying degree. Intra-arterial blood pressure studies were carried out on two patients with paralysis agitans (cases 4 and 6) and the one with multiple system atrophy (case 7). Lewy bodies with or without cell loss were seen in the sympathetic ganglia of five cases of paralysis agitans. Three of these had orthostatic hypotension and the severity of the lesion approximately correlated with the degree of hypotension. It is concluded that the lesions of the sympathetic ganglia may play a major role in the production of orthostatic hypotension in idiopathic paralysis agitans.

Drug therapy in common neurological disorders

Family physicians often see neurological problems, for many of which there is no effective medical treatment. The most common conditions where drug therapy is of value are: headache, neuralgia, seizure disorders, movement disorders, facial palsy, cerebrovascular accidents, and meningitis. The drug treatment in each group is discussed with special consideration to its practical value.