Evidence Of Brainstem Lesion Research Articles

Palatal tremor as a manifestation of epilepsia partialis continua caused by acute precentral gyral infarction

We describe a patient with palatal tremor (PT) as a manifestation of focal seizure caused by acute cortical infarction. Brain MRI showed acute infarction in the left precentral gyrus without evidence of brainstem lesions or hypertrophy of the inferior olivary nucleus. We discuss the differences between our patient and previous reports of symptomatic PT and the mechanisms involved in the development of PT associated with cortical lesions.

Evaluation and graduation of brain stem auditory evoked potentials in patients with neurological diseases.

Based on normative data from 40 subjects, criteria for evaluating brain stem auditory evoked potentials have been elaborated. This system contained six grades from normal to diffusely abnormal, and was used in evaluating recordings from 142 patients, including 38 patients with definite and 48 with probable and possible multiple sclerosis, 18 patients with brain stem infarctions, six patients with other organic brain stem lesions, six patients with a postcommotional syndrome and 26 patients without any brain stem involvement. A statistically significant difference was found between normal persons and patients without evidence of brain stem lesions versus patients with such evidence, as well as between subgroups of slightly and severely affected patients. The system was found useful as a way of describing recordings, in company groups of patients and in a follow up of a few patients.

Cardiovascular autonomic dysfunction in multiple sclerosis is likely related to brainstem lesions

Impairment of cardiovascular autonomic reflexes has been described in multiple sclerosis (MS), and believed reflecting dysfunction of reflex pathways located within the central nervous system. A battery of cardiovascular autonomic tests were performed in 40 patients with definite MS: R-R interval variation test, deep breathing, Valsalva manoeuvre, blood pressure and heart rate responses to standing, sustained handgrip. The results were evaluated by Bayesian analysis, a pattern recognition technique. The patients had also magnetic resonance imaging (MRI) of brain and in 19 subjects of cervical spinal cord. Deep breathing test and sustained handgrip test produced most frequently abnormal results (17.5% and 40%, respectively). However, only 4 patients (10%) had two or more tests abnormal, with a very variable pattern. Evaluation by Bayesian analysis revealed 7 patients (17.5%) with definite autonomic dysfunction. A correlation was found between the confidence level obtained by Bayesian analysis, as index of autonomic function, and the Kurtzke brainstem FS score ( r = 0.43, P < 0.01). There was a significant association between presence of autonomic dysfunction and clinical ( P < 0.02) and MRI ( P < 0.005) evidence of brainstem lesions.

Clinical correlates of abnormal P14 in median SEPs.

Recording median somatosensory evoked potentials (SEPs) from scalp and neck in separate channels with the use of an ear reference, 52 patients had abnormal scalp-recorded P14 associated with normal cervical-recorded N13. The patients had multiple sclerosis or other brainstem or high cervical cord lesions. Evidence of brainstem lesions was found in 35 patients on clinical examination or by brainstem auditory evoked potentials or blink reflex. Abnormalities of P14 were correlated highly with brainstem dysfunction, but high cervical cord lesions could not be excluded by this finding. The localizing value of SEP is improved by measuring the N13 and P14 peaks separately and assessing the cervical cord-brainstem conduction time.

Evaluation of special hearing tests in established central nervous system lesions

The audiological signs of peripheral (Cochlear & neuronal) disorders are well established but those of the central lesions are not well accepted particularly it is true of our Indian populaion. Stevens (1974) suggested that for interpretation of the results of the tests for central auditory disorders, apart from the location and nature of the lesions, the age of the patient, his co-operation, and language proficiency are to be taken into consideration. In this background this study is undertaken to evaluate the performance of 91 cases of the known central nervous system disorders, with conventional and special tests for the retro-cochlear deafness. In later category filtered and staggered speech tests in Hindi were carried out. The results have been correlated with the parallel vestibular and neurological assessments. Total deafness due to very advanced and chronic lesions boldly limited the utility of any audiological test, a problem very special to our population. However, very good correlation was established in 34% cases having positive evidence of brainstem lesions with these special tests, in contrast to 60% cases having positive audiological signs compatable with supra-tentoreal lesions. Vestibular tests however, appear to provide a very valuable assistance in localisation of these central neuro-otological disorders.

The effect of multiple sclerosis on pure tone thresholds.

The pure tone audiograms of 44 multiple sclerosis (MS) and 44 matched neurological control patients were studied with a view to finding out whether demyelinating disease is associated with decreased acuity to pure tones. The results show that MS patients have essentially normal hearing but auditory acuity at some of the low frequencies was found to be significantly worse in the MS group compared to the control patients. No correlation was found between the affected frequencies and the patients' age, sex and duration of the disease. The differences in thresholds between the control and MS patients were confined to the 25 patients who had clinical evidence of brain stem lesions suggesting that the cause of the abnormality in thresholds is in the brain stem.