Gunnar Aschan

Different types of alcohol nystagmus.

In a series of earlier papers, (Aschan, Bergstedt, Goldberg, and Laurell 1955, 1956) positional alcohol nystagmus (PAN) appearing in two phases has been described, with special references to the relationship between PAN and the blood alcohol level. All details will be found in these publications. It should be mentioned here that in normal subjects the two phases of PAN were demonstrated at maximal blood alcohol concentrations as low as 0.02 per cent. This figure seems surprisingly low in comparison with the values reported by earlier authors, who consider that blood alcohol concentrations of 0.06 per cent or more are needed before alcohol nystagmus can be demonstrated clinically. Some of the forms of alcohol nystagmus described earlier have been observed under different conditions, in alcohol-intoxicated patients in a state of unconsciousness (Bernhard and Goldberg 1934), or with the patient looking in the lateral direction and with open eyes (Goldberg 1943). Positional nystagmus described by earlier auth...

Decongestion of Nasal Mucous Membranes by Oral Medication in Acute Rhinitis

Clinical trials of antihistamines combined with adrenergic substances showed a dccongestive effect on nasal mucosal congestion due to acute rhinitis. Double-blind technique combined with objective rhinomano-meiry over 9 hours in each individual trial showed complete absence of placebo effect; the results were therefore conclusive. Tests on 85 subjects with acute rhinitis as well as tests on 50 normal subjects with histamine-pro-voked nasal blocking support the idea that an antihistamine and an adrenergic substance show synergism with regard to nasal decongestion. Of the drugs tested, clemastine combined with phenylpropanolamine gave the best result.

Limb Input to the Cat Vestibular Nuclei

The input from fore- and hindlimbs to the vestibular nuclear complex (VNC) was investigated in awake cats. Electrical stimulus was given to the sciatic, radial and vestibular nerves bilaterally and single unit responses were recorded in the VNC with extracellular technique. The position of the microelectrode was histologically confirmed. All four major vestibular nuclei received fore- as well as hindlimb input. Forty per cent of the neurons with limb input also received vestibular afferents. No major distinguishing features appeared between the different nuclei with regard to response characteristics. Certain differences in laterality of response, quantitative fore-hindlimb ratio and somatosensory-labyrinthine convergence were observed however. Response latencies to sciatic and radial nerve stimuli always exceeded a 3 msec and were grouped around 8 and 16 msec. A third population of vestibular neurons had latencies over 20 msec. Both excitatory and inhibitory responses were recorded, with the latter not always following an activation. The findings illustrate the complex nature of the ascending pathway to the VNC and the integrative properties of this complex.

The Influence of Hypnotic Suggestion on Vestibular Nystagmus

Subjects susceptible to hypnosis, who could also be classified as vestibular “normals”, were selected for the investigation. After a preliminary hypnotic training, they were subjected to rotatory and caloric stimulation using test conditions as close as possible to those used in oto-neurological examinations. The nystagmus induced was recorded behind closed eyelids.Nystagmic responses to vestibular stimuli of similar intensity were measured in five successive tests: (1) control without hypnosis, (2) hypnosis alone, (3) hypnosis and suggestion of decreased rotatory sensation, (4) hypnosis and suggestion of increased rotatory sensation and (5) control without hypnosis.The results showed that in most of the subjects the intensity of the induced nystagmus was lowest under test 3 and highest under test 4. Thus it was usually possible to change the intensity in a desired direction by means of hypnosis and verbal suggestion.In the rotatory tests it was possible to influence both the eye-speed and the duration of...

Xylene Exposure Electronystagmographic and Gaschromatographic Studies in Rabbits

Complaints of vertigo from people who are exposed to industrial solvents have focused interest on their toxic effect on the nervous system. In order to evaluate the influence of an organic solvent, xylene, on the mammalian vestibular system, a series of rabbit experiments were performed. To achieve a constant concentration, the xylene was infused as a lipid emulsion. Blood concentrations were estimated by gas chromatography. Elec-tronystagmography in darkness revealed that at blood xylene concentrations of 30 ppm all rabbits had a positional nystagmus. The beat direction was the opposite of positional alcohol nystagmus. Another difference between the alcohol and the xylene reaction was that rotatory nystagmus responses were exaggerated. The relations between the present findings and the reactions and blood concentrations in people exposed to industrial solvents are discussed.

The Effect of Some Antihistamine Drugs on Positional Alcohol Nystagmus

Introduction.In earlier papers (Aschan, Bergstedt, Goldberg, and Laurell 1955-1956, Aschan and Bergstedt 1956 and 1957, to be published) it was shown that intake of alcohol provokes nystagmus. This nystagmus is partly a vestibular positional alcohol nystagmus (PAN) partly an ocular alcohol gaze nystagmus (AGN). These two forms of nystagmus are of quite different origin and possess different properties; the vestibular PAN appears in two phases, the second one persisting for hours after all the alcohol has left the blood, while the ocular AGN appears only above a certain threshold concentration of alcohol in the blood. An important fact to be noted is that the nystagmus objectively recorded under identical experimental conditions in the same subject varies only slightly as regards time and intensity. It is thus possible to study the effect of different drugs, qualitatively as well as quantitatively, both in the individual subject and in different individuals.

Exposure of rabbits to methylchloroform. Vestibular disturbances correlated to blood and cerebrospinal fluid levels.

SummaryA previously described experimental model for studying the effects on the central nervous system of rabbits, specifically the vestibular apparatus, has been applied to methylchloroform. To achieve a steady concentration the solvent was infused as a lipid emulsion. The blood and cerebrospinal fluid kinetics have been studied. The arterial blood level seems to be closely correlated to the concentration in the central nervous tissue. Vestibular function has been studied by recording the involuntary eye movements — nystagmus — which are elicited via central vestibulo-oculomotor connections. At blood levels of methylchloroform above 75 ppm a so called “positional nystagmus”, indicated vestibular disturbances, is demonstrated. The relationship between the present findings in rabbits and the reaction and blood concentrations in people exposed to industrial solvents, are discussed.

On the Mechanism of Vestibular Disturbances Caused by Industrial Solvents1

The industrial solvents xylene, styrene, trichloroethylene and methylchloroform administered to rabbits caused a positional nystagmus and disturbances in the nystagmus response to rotatory acceleration. The positional nystagmus had a beat direction the opposite to positional alcohol nystagmus, which was in similar experiments elicited by methanol, ethanol and propanol. The three alcohols needed a ten times higher blood concentration to cause a nystagmus than the solvents did.

Positional Alcoholic Nystagmus (PAN) in Man Following Repeated Alcohol Doses

Flourens (1842), in animal experiments, and Joffroy & Servaux (1897), in man, showed that among other symptoms alcoholic intoxication brought about a nystagmus. Barany (1911) and Barany & Rothfeld (1913) found that this nystagmus was influenced by the position of the head of the test subject. Clinical observations regarding alcoholic nystagmus were made by Frenzel (1939), Plenkers (1943) and Walter (1954).This investigation was supported by the Swedish Medical Research Council, Project 25X-36-03.

Clinical vestibular examinations and their results.

Electronystagmography gives objectivation and documentation to the clinical vestibular otoneurological tests. With fixation eliminated the duration of calorically and rotatory induced nystagmus is 30 per cent longer and the eyespeed in the slow phase of this nystagmus up to ten times that recorded under Frenzels glasses.In a large series of patients only one out of ten cases of spontaneous or positional nystagmus recorded behind closed eyelids could be observed directly. At an acute onset of vestibular symptoms the visual influences are negligible, if the onset is insidious or the interval between onset and examination is longer this visual inhibition is more pronounced.It is a reasonable safety requirement that the same examiner should be equally well orientated in both the audiological and vestibular function tests. The diagnosis of a central vestibular lesion cannot be established until the possibility of the findings being of peripheral origin has been excluded. This latter conclusion usually has to ...