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Biomedical subjects

R Sandyk

Publications and source records attributed to R Sandyk.

555 records · Page 31Linked to original sources
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Third ventricular width and its relationship to mode of onset of schizophrenia.

The mode of onset of schizophrenia (i.e., insidious versus acute) may be of neurobiologic and prognostic significance. Schizophrenic symptoms which appear acutely are believed to signify a more benign developmental course and a more favorable outcome of illness than symptoms which emerge insidiously. Since third ventricular enlargement may be a neuroradiological marker of negative schizophrenia, a subgroup of schizophrenia which is associated with poor premorbid adjustment and prognosis, I predict that it will be associated also with an insidious development of disease. To empirically test this hypothesis, I investigated in 22 institutionalized chronic schizophrenic patients (20 men, 2 women; mean age = 31.9 years, SD = 7.1), the association between the mode of onset of schizophrenia and third ventricular width (TVW) on CT scan. In the sample, 15 patients (68.2%) experienced an insidious onset of schizophrenia while 7 patients had a more sudden onset. The two cohorts did not differ significantly on any of the demographic, historic, cognitive, psychopathological, and treatment variables surveyed with the exception of duration of formal education which was significantly shorter in patients with an insidious onset of illness. However, patients with an insidious onset had a significantly greater TVW as compared to those with a sudden onset (M = 7.7 +/- 3.0 mm vs. 4.6 +/- 3.6 mm, p < .05, two-tailed). These findings demonstrate an association between the mode of onset of schizophrenia and TVW on CT scan and suggest that an insult to peri-third ventricular structures, which may underlie third ventricular enlargement, is associated with an insidious development of schizophrenia.

Adult↗
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The relationship between diabetes mellitus and Parkinson's disease.

It has been reported that 50% to 80% of patients with Parkinson's disease have abnormal glucose tolerance which may be further exacerbated by levodopa therapy. Little is known about the impact of chronic hyperglycemia on the severity of the motor manifestations and the course of the disease as well as its impact on the efficacy of levodopa or other dopaminergic drugs. This issue, which has been largely ignored, is of clinical relevance since animal studies indicate that chronic hyperglycemia decreases striatal dopaminergic transmission and increases the sensitivity of postsynaptic dopamine receptors. In addition, evidence from experimental animal studies indicates that diabetic rats are resistant to the locomotor and behavioral effects of the dopamine agonist amphetamine. The resistance to the central effects of amphetamine is largely restored with chronic insulin therapy. In the present communication, I propose that in Parkinson's disease diabetes may exacerbate the severity of the motor disability and attenuate the therapeutic efficacy of levodopa or other dopaminergic agents as well as increase the risk of levodopa-induced motor dyskinesias. Thus, it is advocated that Parkinsonian patients should be routinely screened for evidence of glucose intolerance and that if found aggressive treatment of the hyperglycemia may improve the response to levodopa and potentially diminish the risk of levodopa-induced motor dyskinesias.

Diabetes Complications↗
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Further observations on the unique efficacy of picoTesla range magnetic fields in Parkinson's disease.

External application of picoTesla range magnetic fields (MF) has been reported recently to be efficacious in the treatment of patients with Parkinson's disease (PD) including those who manifest levodopa-related dyskinesias. In the present communication, we present four additional Parkinsonian patients who showed, within a brief period of time, marked improvement in motor symptoms after therapy with MF. Three of the patients had been maintained on antiParkinsonian medication during treatment with MF while the fourth patient had never received pharmacotherapy. Improvement with magnetic therapy was noted not only in the motor sphere (resting tremor, gait apraxia, postural instability), but also in nonmotor aspects of the disease including mood, sleep, pain, anorexia, autonomic, and cognitive functions attesting to the unique efficacy of external picoTesla range MF in the treatment of Parkinsonism. Poverty of facial expression (hypomimia, "masked facies"), which correlates with the degree of striatal dopaminergic deficiency, is one of the clinical hallmarks of PD reflecting the severity of hypokinesia and rigidity in the orofacial musculature. In this report, we emphasize the effects of MF on the hypomimia of PD and provide visual documentation illustrating the changes in the patients' facial expression which follow treatment with MF.

Aged↗
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Autonomic functions in the early stages of Parkinson's disease.

Disturbances of autonomic nervous functions are common in patients with Parkinson's disease (PD) and may develop as a result of pathological changes in centers of autonomic regulation such as the hypothalamus, brainstem, and sympathetic ganglia. We examined cardiovascular reflexes using bedside, noninvasive procedures in 20 unmedicated PD patients with early stages of the disease (stage 1 and 2 on the Hoehn and Yahr's scale). Sixteen patients (80%) exhibited some degree of autonomic nervous system dysfunction. These included predominantly cardiovascular functions mediated via the parasympathetic system. Our findings demonstrate: (a) a high prevalence of autonomic disturbances in early stage PD, and (b) that dysregulation of parasympathetic cardiovascular control mechanisms is a major feature of dysautonomia in early, unmedicated PD patients.

Aged↗
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Pineal calcification and its relationship to the fatigue of multiple sclerosis.

Fatigue is one of the most common clinical features of multiple sclerosis (MS) and is a frequent cause of disability. The pathogenesis of fatigue remains obscure. It may result from impaired propagation of action potentials in areas of demyelination. Other contributors may be mental depression, immobility, and physical disability. The fatigue of MS may be relieved by diverse pharmacological drugs such as amantadine and pemoline, but the mechanisms by which these agents act to ameliorate fatigue are unknown. Attention has been focused recently on the relationship between MS and the pineal gland and evidence has been presented to implicate the pineal gland and melatonin in the pathogenesis of the disease. To investigate this relationship further, we studied in 47 MS patients (mean age: 41.6 +/- 9.9 yrs; mean duration of illness: 13.6 +/- 12.6 yrs) the association between fatigue and incidence of pineal calcification (PC) on CT scan, which is thought to reflect past secretory activity of the gland. For comparison, we also evaluated the incidence of choroid plexus calcification (CPC) in these patients. The sample included 20 patients who experienced ongoing, debilitating fatigue during the course of the disease. 27 patients who did not complain of fatigue served as controls. The two groups were not distinguishable with respect to age, sex, age of onset, chronicity, course (relapsing-remitting vs. chronic progressive), and severity of the disease (ambulatory vs. immobile), as well as the incidence of affective illness.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
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Multiple sclerosis: improvement of visuoperceptive functions by picoTesla range magnetic fields.

The occurrence of cognitive deficits in multiple sclerosis (MS) has been recognized since 1877 when Charcot first observed "enfeeblement of memory" in his patients. Recent studies employing standardized neuropsychological tests have confirmed the high incidence of cognitive deficits in MS patients particularly those with a chronic progressive course of the disease. Visuoperceptive and visuomotor deficits commonly occur in MS patients and are thought to reflect damage to attentional systems due to interruption by demyelinating plaques of nerve conduction along the ascending projections from the brainstem reticular formation to the cortex. Impairment of synaptic conductivity due to serotoninergic depletion (5-HT) may contribute to the emergence of cognitive deficits in MS. The present communication concerns a 36 year old patient with MS in whom external application of picoTesla range magnetic fields (MF) resulted in rapid improvement of symptoms including visuoperceptive functions as demonstrated on various drawing tasks. The report confirms the efficacy of picoTesla range MF in the treatment of MS and demonstrates beneficial effects on cognitive functions as well.

Adult↗
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Treatment of Parkinson's disease with magnetic fields reduces the requirement for antiparkinsonian medications.

Recently, I reported that extracranial treatment with picoTesla range magnetic fields (MF) is an effective, safe, and revolutionary modality in the management of Parkinsonism including those patients manifesting levodopa-induced motor complications. This treatment, which has emerged as a potentially more advantageous modality than pharmacologic therapy, also produces improvements in nonmotor aspects of the disease including mood, cognitive functions, sleep, pain, appetite, autonomic functions, and sexual behavior, which are usually minimally, if at all, ameliorated by long term therapy with levodopa or anticholinergic agents. The present communication concerns a 69 year old Parkinsonian patient who, following a series of two treatments with extracranial picoTesla range MF on two separate days, improved to the point where he was able to discontinue most of his antiparkinsonian medications for a period of two weeks without experiencing deterioration in symptoms. On the third week he began to develop recurrence of symptoms and resumed taking his regular medications. At the end of the fourth week the patient received a series of four magnetic treatments on four successive days after he completely discontinued his antiparkinsonian medications. During this period he experienced a remarkable improvement in motor disability as well as in cognitive functions (i.e., visuospatial performance), mood, sleep, appetite, bowel functions and resolution of pain in the lower extremity. This report attests to the antiparkinsonian efficacy of picoTesla range MF and suggests that this treatment, when applied on a regular basis, may reduce the requirement for antiparkinsonian medications. This observation, when confirmed in a larger cohort of patients, may carry important implications for the therapy of Parkinsonism as it may offer an alternative treatment for patients who develop levodopa failure or experience intolerable side effects from dopaminergic medication. The observation that magnetic treatment improved the patient's symptoms while being off dopaminergic therapy supports the role of nondopaminergic mechanisms in the pathophysiology of Parkinsonism.

Aged↗
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Drug-induced parkinsonism: relationship to age at onset of schizophrenia.

On the basis of the association of negative schizophrenia with parkinsonism and early age of onset, we predicted that the latter two would covary, as reflecting a similar pathological process. To test this prediction, we studied in 40 neuroleptic-treated female schizophrenic patients with drug-induced movement disorders the association of age at onset with drug-induced parkinsonism and, for comparison, also with persistent tardive dyskinesia (TD) and acute drug-induced dystonia. We found that onset of schizophrenia during adolescence, significantly predicted the presence of parkinsonism but, by contrast, was unrelated to TD and acute drug-induced dystonia. Our findings suggest a specific association between early age at onset of schizophrenia and parkinsonism, implying that the former may be a risk factor for parkinsonism. The significance of these findings to the pathophysiology of negative schizophrenia and parkinsonism are discussed.

Adult↗
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Melatonin secretion and the pathophysiology of Meige's disease (idiopathic orofacial dystonia): a hypothesis.

Meige's disease is a form of focal dystonia characterized by symmetric dystonic spasms of facial muscles, sometimes associated with dystonic movements of other midline muscle groups. The etiology and pathophysiology of the disease have not been established. There is evidence that Meige's disease may result from striatal dopaminergic preponderance coupled with cholinergic overactivity. Several authors have noted a high prevalence of depression in patients with Meige's disease, suggesting a common neurochemical abnormality. Depression, in turn, is associated with decreased pineal melatonin secretion. We propose, based on studies demonstrating that melatonin regulates dopaminergic, cholinergic and GABA-ergic functions, that alterations in melatonin functions may enhance the development of the disease. This hypothesis may open new avenues toward understanding the pathophysiology of the disease and developing newer therapeutic strategies.

Bipolar Disorder↗
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Edentulousness and neuroleptic-induced neck and trunk dyskinesia.

Edentulousness, by disrupting trigeminal propioceptive input from the oral cavity to the basal ganglia, may increase the risk for neuroleptic-induced orofacial dyskinesia. Since lesions of the globus pallidus alter trigeminal sensory-induced reflexive neck muscle activity in rats and the putamen-caudate complex regulates vestibular and propioceptive mechanisms, edentulousness could facilitate also the expression of neuroleptic-induced neck and trunk dyskinesias. In a sample of 131 neuroleptic-treated chronic schizophrenic patients, we found that edentulous patients exhibited significantly more neck and trunk dyskinesias as compared to nonedentulous patients (p less than 005). By contrast, dyskinesias of the face, tongue, and extremities did not differ between the two cohorts of patients. Our findings imply that edentulousness may increase the risk of neck and trunk dyskinesias and highlight the importance of the dental status in tardive dyskinesia.

Adolescent↗
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Opioid-serotoninergic dysregulation in the pathophysiology of Tourette's syndrome.

In the following communication the major neurotransmitter systems postulated to be involved in the pathophysiology of Tourette's syndrome are discussed. Malfunctions of the opioid and serotoninergic systems are discussed regarding their role in the pathophysiology of the neuropsychological, behavioural and other manifestations of the disease.

Brain↗
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Post-amputation phantom pain and autonomous stump movements responsive to doxepin.

A 40-year old man with post-amputation phantom pain and involuntary autonomous movements experienced dramatic relief of both pain and autonomous movements with administration of the antidepressant doxepin. The pathophysiology of pain and post-amputation autonomous movements, as well as the therapeutic response to doxepin are discussed in terms of the effects of limb amputation on spinal excitability and alterations in both spinal and supraspinal transmitter functions.

Adult↗