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Morphological and biochemical findings are described from the brain biopsy of an 11-year-old girl with intractable type II epilepsia partialis continua. Computerized tomography scan showed severe progressive central and cortical atrophy, mainly of the right hemisphere. Brain biopsy revealed microangiopathy of the cortex-penetrating arteries, patchy necrosis of the cortex, and small loose infiltrates of lymphocytic cells. Biochemical analysis showed normal pyruvate metabolism and citric acid cycle in gray and white matter.

A 62-year-old woman with cervical myelopathy due to cervical spine rheumatoid arthritis is presented. Transoral decompression of the spinal cord, followed by posterior spine fusion in the same session was performed with good results. Unfortunately she died 3 months later due to cardiovascular disease. Clinical, radiological, surgical and autopsy data are presented.

Ocular motor tests performed on 14 patients with idiopathic spasmodic torticollis were normal. The vestibulo-ocular reflex tested in eight patients showed a significant high level in seven. It is suggested that this phenomenon is secondary rather than the cause of spasmodic torticollis.

The direction of eye movement (i.e., the angle of the resultant velocity vector calculated from the horizontal and vertical components) during flash-induced nystagmus was evaluated in static roll and pitch positions. It appeared that this direction coincided with the orientation of the visual streak, as influenced by the ocular countertorsion which is known to occur in the various body positions. This supports the hypothesis that flash-induced nystagmus results from stimulation of direction-selective retinal elements. The intensity of flash-induced nystagmus, evaluated either by measuring slow-phase velocity (i.e., magnitude of resultant vector) or by beat frequency, was minimal in approximately 90 and 270 degrees roll or pitch positions, presumably because the total combined (utricular and saccular, left and right) excitatory otolith stimulation was maximal in these positions, the effect of this stimulation being inhibitory to the flash-induced nystagmus.

The results of clinical and electrophysiological investigations in a patient with a locked-in syndrome due to a pontine infarction, mainly on the right side, are presented. EEG showed only slight disturbances, while BAER and SSER revealed response alterations as could be expected from physical examination. BAER revealed altered central conduction after stimulation of either side. After median nerve stimulation on the right side SSER was slightly delayed, while no reproducible cortical response was seen after stimulation on the left side. Our patient survived and showed partial recovery.

After bilateral labyrinthectomy the maximum slow phase velocity of flash-induced nystagmus (FIN) was diminished; the flash induced after-nystagmus was always absent. Unilateral labyrinthectomy resulted in a weaker FIN response on stimulation of both eyes, but the best response was seen after contralateral stimulation. These findings are discussed in relation to reported effects of labyrinthectomy on OKN, "central nystagmus" and vestibular nuclear discharge activity.

Flash-induced nystagmus (FIN) was found more often in albino than in pigmented rabbits. Incremental and decremental phase mainly showed exponential change in SPV, but linear change was seen as well with apparent time constant of 5-40 sec. FIN was unaltered by rendering the stimulated eye akinetic. Lesioning the nucleus of the optic tract (NOT) on one side abolished FIN and OKN responses from the other side. Bilateral labyrinthectomy led to a diminished response and after-responses were lost. Algebraic addition was shown if FIN was combined with vestibular reflex eye movements. The gain of these reflexes was enhanced. FIN may be specified as a type of nystagmus that is evoked by monocular essentially open-loop stimulation of the crossed ('subcortical') optic pathway. Direction-selective elements in the retina may play a specific role in that their predominant orientation gives rise to abduction nystagmus during on/off stimulation by flashes.

Flash-induced nystagmus (FIN) was elicited by monocular flicker-stimulation at 20-40 Hz. It was found more often in albino than in pigmented rabbits. Slow phase velocity (SPV) showed a gradual increase, then a steady-state level in most animals and an after-response after cessation of stimulation. incremental and decremental phase mainly showed an exponential change in SPV. Apparent time constants were in the range of 5-40 sec. Simultaneous recording of both eyes revealed greater velocity and amplitude of both phases of FIN in the stimulated eye. FIN can be specified as a type of nystagmus that is evoked by monocular essentially open-loop stimulation of the crossed ("subcortical") visual pathway. Direction-selective elements in the retina may play a specific role and their predominant orientation gives rise to nystagmus in adducting direction in the flicker-stimulated eye as if it were exposed to optokinetic stimulation in the temporonasal direction.

A family is described with a progressive autosomal dominant vestibulocochlear dysfunction resulting in a Dandy syndrome, head movement dependent oscillopsia and hearing loss. The history was negative for other neurological or otological diseases (including infectious diseases) or use of neuro-ototoxic drugs, except for a high incidence of vascular disorders (hypertension, stroke, and heart infarction).

Three members of a single family with the symptom of "motion sickness" showed rebound nystagmus, saccadic pursuit eye movements, defective optokinetic slow phase velocity and lack of fixation suppression of vestibularly induced nystagmus. One of them showed vestibular hyperreactivity and a gradual build-up of the optokinetic response. In absence of other abnormalities, these findings can be localized to the vestibulocerebellum (flocculo-nodular lobe).

A kindred is presented in which several members had complaints of head movement-dependent oscillopsia due to acquired vestibular areflexia in combination with progressive hearing loss. History was noncontributory for other neurologic or otologic diseases (including infectious diseases) or use of neuro-ototoxic drugs. The pedigree suggests autosomal dominant inheritance.

The gain in the optokinetic nystagmus reflex (OKR) of 27 labyrinthine-defective patients was compared with that of 27 subjects without any otoneurological abnormality, who were matched by age and sex. The patients without labyrinth function exhibited significantly higher OKR gains than the control subjects, especially so at higher age. The observed enhancement of OKR gain in the absence of vestibular function is ascribed to the effect of optokinetic training brought about by enhanced slippage of retinal images due to lack of an efficient vestibulo-ocular reflex.

The correlation between velocity step (VS) and caloric response parameters was studied in a series of several hundred patients who underwent a neuro-otological examination. The VS parameters initial velocity (V in degree/s), time constant (T in s) and Gesamtamplitude G ( = VT in deg) were all significantly correlated with the caloric response parameters. The highest correlation coefficients were associated with G.

In a series of 600 patients, 10 showed unilateral hyperactive caloric responses without a trivial explanation such as spontaneous nystagmus or directional preponderance. All 10 had unilateral weakness on the contralateral side, which was accompanied in 9 by cochlear hearing loss. It is assumed that the phenomenon of unilateral hyperreactivity in these cases can be explained by release from commissural inhibition on the basis of temporary vestibular decompensation.