Acoustic neuromas (diagnostic value of testing the function of the trigeminal nerve, the cerebellum and optokinetic nystagmus).

The involvement of the trigeminal nerve, cerebellum, and optokinetic nystagmus in patients with acoustic neuromas, as well as the methods of investigation, are described. The corneal and/or facial sensibility was found to be reduced in 29 per cent of the whole series and in 53 per cent of tumors larger than 40 mm. There was a significant correlation between reduced corneal and/or facial sensibility and the findings of pressure at the trigeminal root at operation. Only three patients had a persistent reduction of trigeminal function post-operatively. Cerebellar dysfunction was found in 32 per cent, but significantly more frequently (58 per cent) in patients with tumors larger than 40 mm. Post-operatively, six patients had cerebellar symptoms in the form of gait disturbances; five of these patients had a supplementary suboccipital removal performed, after the initial translabyrinthine approach. A defective optokinetic nystagmus was found pre-operatively in 10 patients, nine of whom had tumors larger than 40 mm in diameter. All patients with a defective optokinetic nystagmus had a large anatomic impression in the pons at operation. In patients suspected of having an acoustic neuroma, symptoms from the trigeminal nerve, the cerebellum and the optokinetic nystagmus predict the presence of a large tumor and subsequent difficulties at operation. The symptoms were completely reversible in the vast majority of cases and post-operative symptoms persisted only in patients in whom tumor removal was difficult and the tumor very large. Testing of the trigeminal nerve, the cerebellum and the optokinetic nystagmus still deserves its place in the diagnostic work-up of patients with unilateral acoustic or vestibular symptoms, especially in cases with severe hearing impairment, which necessitate the use of tests that are independent of acoustic function.

Spontaneous nystagmus in central nervous disease.

Over a 10 yr period, 23,899 patients from the neuromedical and neurosurgical departments were examined for spontaneous nystagmus. A central spontaneous nystagmus was found in 281 patients (1.2%).

Prognosis in infantile hydrocephalus. Follow-up in adult patients, born 1946-1955.

Twenty-six patients with infantile hydrocephalus were re-examined at ages ranging from 21-32 years. Operations had been performed in 11, but abnormal head growth continued post-operatively in 9. One third of the patients lead a normal life, while half of the patients are mentally deficient. All patients have neurological signs, poor dexterity and clumsiness being present in all. Psychological testing reveals uneven profiles, in 4 patients with performance IQ considerably lower than verbal IQ. Computerised tomography demonstrates all degrees of hydrocephalus with no correlation between ventricular-brain ratio and IQ or between ventricular-brain ratio and operative procedures. Full otoneurological investigation shows differential-caloric examination to be abnormal in 60%, although none of the patients have complaints referring to the vestibular system.

Vestibular dysfunction in occupational chronic solvent intoxication.

Neurotoxic volatile organic solvents used by house and car painters may lead to professional toxic encephalopathy after several years of exposure. The symptoms are memory impairment, fatigue, personality changes, headache and dizziness. Vestibular dysfunction was found in 55% of 113 painters examined, mainly in the form of reduced caloric vestibular reactions. No correlation between vestibular dysfunction and the duration of exposure, cerebral atrophy or intellectual impairment could be demonstrated. Vestibular examination may be helpful in detecting early changes in exposed persons and in determining more accurate safety limits for harmful chemicals.

Computer analysis of electronystagmographic data.

Manual calculation of the parameters of nystagmus is imprecise and time consuming. Therefore, a computer program for analysis of nystagmus has been built up in our laboratory. The program is based on automatic extraction of the minimum and maximum values nystagmus. These values are stored for calculations of duration, amplitude and velocity of the fast and slow phase. The distinction between the slow and fast phase is based on the duration of the phases. The program is thus able to accept nystagmus in different directions.

Bilateral loss of caloric response in conscious patients (areflexia vestibularis).

Twenty-six of 11 793 consecutive vestibular examinations showed no vestibular response to bilateral irrigation with 20 degrees C water (areflexia vestibularis). CNS malignancies, infections, congenital disorders, drugs and various central nervous system disorders were found to be the most frequent aetiological factors. Associated sensorineural hearing loss--infection expected--was an uncommon finding as 17 of 26 examinations showed no auditory impairment.

Central vestibular involvement in peroneal muscle atrophy: a preliminary report.

A family is presented in which 6 out of 8 members were found to have peroneal muscle atrophy. Neurophysiological and histopathological evidence for the hypertrophic form of this disease was obtained in 3 patients. Three patients with peroneal muscle atrophy and 1 unaffected family member had abnormal differential caloric tests. This is the first report of an apparently hereditary dysfunction of the central vestibular system associated with a hereditary neuropathy.

Parosmia.

Changes in the sense of smell may be quantitative. The latter are called parosmia. Various forms of central and peripheral parosmia are described. The treatment is mentioned.

The profile and severity of lithium-induced side effects in mentally healthy subjects.

In a double-blind, placebo-controlled, crossover design various side effects (= unwanted effects) during 6 months of therapeutic serum lithium levels (0.7-1.1 mmol/1) to nonpsychiatric patients were studied. The side effects were measured by self-rating scales and independent observer rating scales administered every 2-4 weeks throughout the study. After months of treatment, lithium induced hand tremor and thirst/polyuria; however, without any relationship to the serum levels of lithium. The frequency of tremor was highest in patients above the age of 60 years. No initial sedative-like lithium effect was found.

Meniere's disease: a neuropsychological study II.

23 Meniere patients were examined with an extensive battery of neuropsychological tests. In a previous investigation the authors had demonstrated that patients with a long duration of Meniere's disease had psychological disturbances, presumably localized in the nondominant hemisphere. In the present investigation the patients had a short duration of the disease, and we were unable to reproduce the psychological disturbances. It is concluded that the central changes in the nondominant hemisphere function develop over a long period of time. It is hoped for that further neuropsychological investigations of Meniere patients can give more information of what is primary in Meniere's disease: peripheral sensory or central neurological changes.

Vestibular function in benign intracranial hypertension.

Investigation of vestibular function in 34 patients with benign intracranial hypertension was performed and a follow-up examination 3-20 years after the primary examination, when the symptoms of intracranial hypertension had disappeared. A primarily affected vestibular function was found in 19 patients (56%), viz. hyporeactivity in 9, preponderance in 9, and hyperreactivity in 2. Except for 2 patients, all had normal vestibular reactions at follow-up. These patients exhibited no evidence of what is called 'congestive inner ear'. An account is given also of the role of vestibular testing in connection with brain death criteria and recent experience of continuous monitoring of intracranial pressure.

Positional nystagmus of the persistent type.

In a 6-year period (1970-1975), a total number of 10,730 patients were examined oto-neurologically by the same physician, all of the patients being referred from the neuromedical and neurosurgical departments. Persistent positional nystagmus is in this material the same as central positional nystagmus, because the lesion in all cases was of central origin. Central positional nystagmus was found to be a rare symptom, since it was only demonstrated in 124 patients (1%). Central positional nystagmus was defined as being with no latency, low and irregular frequency, nonfatiguable with no accompanying dizziness, and the patients examined in the following positions: right and left side, supine and with hanging head. In 52 cases (42%) the nystagmus was only demonstrated with hanging head. The diagnoses were dominated by intracranial tumors (34 infra-tentorial, 19 supratentorial). Among other diagnoses encountered were intracranial vascular disease, encephalopathia, epilepsy and multiple sclerosis. 21 patients were children under 15 years of age, and in this group the intracranial tumors, especially the infratentorial, were even more dominant.

Menière's disease. II. A neuropsychological study.

23 Menière patients were examined with a extensive battery of neuro-psychological tests. In a previous investigation, the authors had demonstrated that patients with long-duration Menière's disease had psychological disturbances, presumably localized in the nondominant hemisphere. In the present investigation, the patients had short-duration Menière's disease, and we were unable to replicate the results of the former investigation. It is concluded that the central changes in nondominant hemisphere function develop over a long period of time. It is hoped for that further neuropsychological investigations of Menière patients will give more information on what is primary in Menière's disease: peripheral, sensory or central neurological changes.

Meniere's disease. A neuropsychological study.

A neuro-psychological study is described comprising 19 patients with Meniere's Disease who were participating in an experimental lithium therapy programme. The patients evidenced an organic dysfunction which is not entirely periphearl. The interpretation of the results are not incompatible with an attempt to reconcile neuro-psychological and psycho-somatic viewpoints regarding etiological aspects of Meniere's Disease. An evaluation of the lithium effect was performed.

Cerebellopontine pantopaque cisternography and tomography of the internal acoustic meatus in the diagnosis of angle tumors.

The results of 106 consecutive Pantopaque cisternographies performed at the neuro-radiological department, Rigshospitalet, are presented. 41 positive and 65 negative examinations were found. Good accordance between radiological tumor size estimation and size of actual, surgically verified tumor was noted. A comparison between tomography of the internal auditory canal and pantopaque cisternography of the posterior fossa has been made, and we found 6 cases with normal tomography and positive cisternography. Furthermore 17 cases (26%) with pathological tomographic examination of internal auditory canal as well as a negative finding at Pantopaque cisternography, were encountered. Therefore we conclude that asymmetry of the radiological appearance of the internal auditory canal at tomography is not of decisive importance in the indication for cisternography, but the examination should be included in the test battery in search for cerebellopontine angle pathology. We agree with other authors that Pantopaque cisternography is without any doubt the final and most conclusive examination available for the diagnosis of cerebellopontine angle tumors. A system of grading the different objective findings giving indication for Pantopaque cisternography has been made.