[Evaluation of VIIIth nerve disorders in learning-disabled children]

Recent research indicates that a subclinical VIIIth nerve defect can be a major contributing factor to, if not a cause of learning disabilities. A battery of tests developed for evaluation of VIIIth nerve function is presented. These tests include assessment of vestibular function and evaluation of auditory figure ground abilities. 70 primary school children diagnosed as learning-disabled by child study teams were tested using this battery. 94% had abnormal findings in the electronystagmographic test and 22% in the auditory figure ground test. This battery of tests can detect subclinical defects in learning-disabled children which can be alleviated by a combination of proper medical treatment and an appropriate educational plan.

Vestibular neuronitis in childhood

Over a 14-year period commencing in 1973, we followed 177 children less than 12 years old suffering from vertigo and/or disequilibrium. In 35 of 177 patients, the vertigo-like condition was due to peripheral causes: 10 sudden deafness, six vestibular neuronitis, three benign paroxysmal positional vertigo and three Meniere's disease. In this paper, two cases of pediatric vestibular neuronitis will be reported in detail. All six patients with vestibular neuronitis were boys, and the affected sides were equally distributed in the group. The patients recovered within two to four weeks, a prognosis which is better than that observed in adults. With regard to directional nystagmus, the gaze was bilateral in five patients and vertical in two. They showed neuro-otologic findings that suggest not only unilateral dysfunction but also bilateral disorders or partial lesions on the central vestibular system. Consequently, in the hope that the study of vertigo in childhood may provide additional clues to the pathogenesis of the disease in adults, we would like to consider two cases of pediatric cases of vestibular neuronitis.

Diagnosis and management of vertigo

Patients with vertigo may be best evaluated when the physician has the various entities that may be responsible clearly in mind. Those diseases listed in group II are more familiar to the primary care physician than those listed in group I, which belong more in the realm of neuro-otology than in general medicine and neurology. The proper use of history, physical findings, and laboratory evaluations will allow the clinician to classify the patient's problem and to initiate treatment and consider appropriate referral when indicated.

Dégénérescence systématisée optico-cochléo-dentelée

During the first year of life a girl, the first child of non-consanguineous parents, developed a progressive neurological disease characterized by blindness, severe hypotonia, impaired motor development, microcephaly and mental retardation. Later she became unresponsive to auditory stimuli. She died at the age of 13 months. Post-mortem examination revealed atrophy of the optic nerves and chiasm, lateral geniculate nuclei and superior colliculi, degeneration of the cochlear nerve roots, dorsal and ventral cochlear nuclei, superior olives, lateral lemnisci, medial geniculate nuclei and inferior colliculi and atrophy of the dentate nuclei, hilus and superior cerebellar peduncles. These were consistent with dégénérescence systématisée optico-cochleéo-dentelée. Additional abnormalities included degeneration of the posterior columns in the spinal cord, gracilis and cuneate nuclei and medial lemnisci, atrophy of the spinocerebellar tracts and Clarke's columns, cerebral cortex, cerebellum, chiefly involving the rostral vermis, inferior olivary nuclei and demyelination of the sural nerves.

Subacute polyradiculopathy with optic and auditory nerve involvement

Two patients are described, who, after an otherwise trivial viral upset, presented with an acute syndrome consisting of polyradiculopathy affecting all four limbs, with additional severe optic and auditory nerve involvement and other central nervous system signs. A combination of some of the features of the Guillain-Barré syndrome and a simultaneous acute episode of demyelination in the central nervous system were seen in these patients.

Acute bilateral sequential vestibular neuritis

Two cases of bilateral sequential vestibular neuritis demonstrate the significant persistent disequilibrium that follows involvement of the second ear. The etiology for the loss of vestibular function is postulated to be a viral neuritis. Vestibular suppressant drugs are helpful in relieving nausea and vomiting in the acute phase of the disease; however, they are of no therapeutic value for the protracted disequilibrium following involvement of the second ear. An awareness of this disorder as a disease entity will minimize diagnostic and therapeutic frustration on the part of the physician and provide a realistic prognosis for the patient. Unfortunately, the prognosis is for permanent but somewhat lessening disequilibrium with the passage of time and depends in great part on the subject's age.

Paroxysmal tinnitus and nystagmus accompanied by facial spasm

A case of paroxysmal tinnitus and nystagmus, accompanied by facial spasm, in which neurovascular decompression was performed, is reported. The paroxysmal tinnitus and nystagmus were synchronous with each other. Horizontal nystagmus with a rotary component was found to be counterclockwise during the brief attack of tinnitus, whereas its direction became clockwise while free of tinnitus. The patient has been postoperatively relieved not only of the facial spasm, but also of the tinnitus and nystagmus. The mechanism of the occurrence of the syndrome and the significance of the neurootologic examination are discussed.

Dizziness in childhood

Dizziness in childhood is not an infrequent symptom. Accurate history taking and close co-operation between otologist, paediatrician and neurologist are necessary in the approach to the dizzy child. Most cases of childhood dizziness settle in time and investigations should be carefully selected; those with severe and persistent dizziness or ataxia should be thoroughly investigated including: EEG, ENG, calorics and CT scan. The conditions causing dizziness in children are discussed and are illustrated with case histories from our series of 27 children. Dizziness of unknown aetiology, serous otitis media and benign paroxysmal vertigo were the most common diagnostic labels applied to our patients. Treatment is rarely necessary but dimenhydrinate or a labyrinthine sedative in those with troublesome vertigo, or the adjustment of the medical regime in those epileptics on phenytoin, may be beneficial. Surgical intervention is only required in those with an operable lesion.

[Case of tinnitus, vertigo, and a loss of caloric response due to neurovascular compression]

The authors report a case of neurovascular compression of the eighth cranial nerve in a 49-year-old businessman. The patient was admitted to the University of Tokyo Hospital because of progressive vertigo and tinnitus on the right without hearing loss over the seven years prior. There were no other symptoms. The general examination was normal. He was neurologically intact except for loss of caloric response. Audiometric studies and brain stem response were normal. The findings of routine hematology, biochemistry, and serology were within normal limits. Tomogram showed that right internal auditory meatus was wider than the left by 2 mm. Computed tomography with metrizamide demonstrated a filling defect in the right cerebellopontine angle. We decided to proceed with exploratory operation with the tentative diagnosis of a left cerebello-pontine angle mass, perhaps neurinoma en plaque meningioma, or epidermoid tumor. Left retromastoid craniectomy with microsurgical exploration of the cerebellopontine angle revealed not a tumor, but a loop of the anterior interior cerebellar artery (AICA) compressing the eighth cranial nerve close to the porus acousticus. A piece of muscle was inserted between the eighth cranial nerve and the AICA. His postoperative course was uneventfull with complete relief of symptoms and without impairment of hearing. In patients with hemifacial spasm and trigeminal neuralgia, neurovascular compression (NVC) has been found at the root entry zone of the facial or trigeminal nerves close to the brain stem at the "junction zone" on the glia and schwann sheath of these nerves.(ABSTRACT TRUNCATED AT 250 WORDS)

Vestibular neuronitis; a neurological and neurophysiological evaluation

Neurological and neurophysiological findings were retrospectively reviewed in a group of 50 patients with vestibular neuronitis (VN). The onsets of VN were found to be clustered in the period from August to January. A preceding infection was reported by 36% of the patients. Neurological examinations did not reveal any other relevant signs than a spontaneous nystagmus during the acute phase. The results of routine laboratory tests and cerebrospinal fluid tests were within normal limits. EEG was recorded in 37 patients; 15 patients had a definitely abnormal EEG, with a slowing of the dominant occipital rhythm or more generalized diffuse slowing in 12 cases. 5 patients, 3 of them without slowing of the background activity, had a distinct focal disturbance of intermittent slow activity in the temporal region. In control recordings, an improvement was seen in the slowing of the background activity but not in the focal disturbances. Brainstem auditory evoked responses (BSER) were recorded in 12 patients, 5 of whom had abnormal responses. The seasonal clustering of VN onsets and the association of VN with overt infections further suggest its infectious pathogenesis. The observed EEG and BSER disturbances suggest a subclinical brainstem involvement in some cases of VN.

Evaluation of diagnostic audiometric tests

Five diagnostic audiometric procedures - acoustic reflexes, performance-intensity functions for monosyllabic (phonetically balanced) words, Békésy audiometry, Békésy comfortable loudness audiometry and suprathreshold adaptation test - were critically evaluated by decision matrix analysis and information theory analysis. The subjects were 20 patients with surgically confirmed eighth nerve disorders and 20 patients with presumed cochlear disorders. Each patient completed all test procedures. In terms of decision matrix analysis, sensitivity (correct identification of eighth nerve site) ranged from 45 to 85%. Specificity (correct rejection of patients with cochlear site) ranged from 70 to 100%. Predictive value ranged from 74 to 100% for positive results and from 62 to 82% for negative results. The efficiency of the five tests ranged from 68 to 78%. In terms of information theory, positive test results increased the probability of eighth nerve disorder in any subject from 50% (a priori) to 74-100%. Negative test results decreased the probability of eighth nerve disorder from 50% to 18-38%. Relative differences among the diagnostic effectiveness of the five individual test procedures were not pronounced. However, the suprathreshold adaptation test (results confined to 500, 1 000 and 2 000 Hz) was less efficient than the other four diagnostic techniques.

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.

Sudden hearing loss in the contralateral ear in postoperative acoustic tumor: three case reports

Careful presurgical otologic assessment of the contralateral ear in acoustic tumor patients is essential, not only to establish baseline data but more importantly to resolve the intense patient anxiety that arises almost immediately when the diagnosis is presented. Any subsequent reduction in hearing acuity in the contralateral ear after the tumor ear has been deafened, poses serious psychological, socio-economic and medical problems. Three detailed case reports of sudden hearing loss in the contralateral ear of postoperative acoustic tumor patients are presented. The lesion sites include: the middle ear, cochlear, and retrocochlear. In each case, hearing returned to its previous or near-previous levels. Allergic factors were implicated in two cases.

Cochlear nerve degeneration coincident with adrenocerebroleukodystrophy

A 19-month-old boy had adrenocerebroleukodystrophy and unusually severe cochlear nerve degeneration and demyelination, a condition in advance of that expected from known disease entities. We report the only known temporal bone study in adrenocerebroleukodystrophy.