[Bidirectional horizontal and tridimensional apogeotropic nystagmus: 2 semeiological realities]. / Il nistagmo orizzontale bidirezionale e apogeotropo tridirezionale: due realtà semeiologiche.

The authors take into account two different types of stationary, persistent and direction-changing nystagmus (ny): 1) the horizontal bidirectional ny (nyOB), apogeotropic (nyOBA) and geotropic (nyOBG); 2) the tridirectional apogeotropic ny (nyAT). The nyOBA was identified in experimental studies in 1973 but no other studies on the subject have been published since then. In existing literature the nyOBG has been reported in only one paper, whereas the nyAT has not yet been studied at all. The nyOBA is the combination of a 2nd degree left ny with the head turned right and a 2nd degree right ny with the head turned left. The nyOBG is the combination of a 2nd degree right ny with the head turned right and a 2nd degree left ny with the head turned left. The nyAT is a 2nd degree apogeotropic ny noticeable with the head turned left, right and in the position of Rose (head hanging down). From among a total of 5,960 consecutive vestibular examinations performed from 1986 to 1990, the authors chose those presenting nyOBA, nyOBG and nyAT and discuss them in the light of other vestibular findings and clinical diagnosis. A routine vestibular examination aims at verifying an eventual, spontaneous/evoked ny with the head turned right and left, in the position of Rose and in the two rapid Hallpike positionings. Frenzel glasses are used for detecting the gaze and rebound ny and these, in turn, are checked for visual fixation. During the caloric stimulation, according to the Fitzgerald-Hallpike method, the ny visual suppression test is performed at the culmination period. When electronystagmography is performed, visual oculomotor reflexes are often tested as well. The nyOB and/or nyAT were observed in 3.9% of the patients (234 subjects). The nyOB was present in 177 patients as follows: apogeotropic ny in 128 and geotropic in 49. This was the only vestibular finding in 46.9% of the nyOB cases (83 out of 177 patients). The nyAT was observed in 57 patients and in 17.6% of them was the only pathological finding of the otoneurological examination. When nyOB or nyAT were observed, clinical diagnosis evidenced their central origin in 138 of the 234 patients, most frequently present in cranial trauma, vertebral-basilar vasculopathy and multiple sclerosis. In a limited number of cases some sign of peripheral vestibulopathy were also observed.(ABSTRACT TRUNCATED AT 400 WORDS)

Electronystagmography in the diagnosis of multiple sclerosis.

The aim of our study was to define the diagnostic importance of a complete electronystagmographic (ENG) examination (visual-vestibular, vestibular and visual suppression tests on caloric nystagmus) in patients affected by MS. Of 144 patients examined, 116 were definite and 28 possible. Descriptive data of the instrumental findings showed very frequent alterations of one or more subtests: pursuit movements and visual suppression test were especially pathological, in respectively 56% and 58% of the cases; spontaneous and/or evoked nystagmus was present in 45%. A comparison between clinical and instrumental evidence of brainstem/cerebellar involvement indicated that 18% of the definite and 32% of the possible MS cases presented a negative clinical examination with positive instrumental findings. The usefulness of including a comprehensive ENG examination to obtain paraclinical evidence of a second lesion in the CNS in early MS is discussed.

[Oculomotor findings in the stages "on" and "off" in Parkinson disease patients]. / Reperti oculomotori nelle fasi "on" e "off" di pazienti affetti da morbo di Parkinson.

To study the possible damage of oculomotor structures we have studied 10 patients affected by idiopathic Parkinson's disease with a clear on-off phenomena. All the patients were subjected to an electro-oculographic examination observing qualitative and quantitative parameters in both on and off phases. The two exams were carried out in the same morning. We observed the well known electro-oculographic pattern of parkinsonian syndrome: multiple steps saccades, pursuit alterations, absence of spontaneous or evoked nystagmus. Moreover the most relevant finding consisted in an improvement of some electro-oculographic features during the off phase, contrary to clinical evidence. Such results seem to suggest that oculomotor system is functionally separate from that which controls arm movements.

Electro-oculographic routine examination in Parkinson's disease.

The authors studied a group of 36 patients with idiopathic Parkinson's disease by electro-oculographic examination in order to evaluate the most frequent vestibular and oculomotor findings. Vestibular alterations were detected mainly in caloric nystagmus (82.9%). Hyperreflectivity was the most frequent evidence, but it does not necessarily represent the sign of a lesion. The occurrence of spontaneous and evoked nystagmus was not significant. Oculomotor findings were more interesting, as they were altered in two-thirds of the cases. Particularly, saccadic eye movements presented a "multiple step" morphology in 58.3% of the series. This saccadic disarrangement was scarcely found in neurological patients with brainstem and/or cerebellum pathology (7.7%). Moreover, in Parkinson's disease patients no other saccadic alterations typical of brainstem or cerebellum involvement were found. Such observations suggest a possible non-cerebellar origin of "multiple step". Vestibular and oculomotor findings were not significantly correlated with the clinical features of the patients.