Category Archives: Central Vestibular Disorders

Isolated Skew Deviation

Here’s a very peculiar case of a 63yr male with acute vertical diplopia, more pronounced when looking down which makes him feel dizzy and unstable all the time especially when looking downwards. He came to my office 7 days after the beginning of his symptoms.

The only thing I’ve noticed was skew deviation discovered at cross cover test with the hyperphoria of the right eye and hypophoria of the left eye.

I’ve asked for MRI which disclosed a punktiform lesion at mesencephalon.

Skew Deviation

Skew deviation

Skew deviation
This case is open for discussion.

Wallenberg or lateral medullary syndrome

74yr woman with acute vestibular syndrome 10days old, but with still pronounced instability.
She has diabetes and hypertension.
On first day she was hypertensive 200mmHg and with described 3rd grade of Ny to the right. Because CT was ok she was dismissed.
On a second day again at emergency unit there was not described Ny nor any of neurological deficits.
She complains on instability, light headache at frontal part, weakness in left hand and left leg; hoarseness and difficult swallowing (feeling like she is going to choke, but she didn’t).

She can’t stand alone nor sit without support.
There’s no spontaneous Ny, but discrete gaze evoked to the left (when looking slight upwards) with slight torsional cw component.
Horner’s sign on the left side. (slight ptosis, with miosis and facial anhydrosis)
Left side of face was less sensitive and palatal reflex absent, but normal function of the vocal folds. Cerebellar sign showed bradikinesia at both sides and dysmetria at left side.
Head impulse test was slightly positive to the left (hardly visible, not obvious).

VHIT: showed slight reduction of the VOR to the left, but what was strange it varied (sometimes good, sometimes bad, but without compensatory saccades)

stroke-vhit-bad VHIT stroke PICA

VNG (tracking and saccades in horizontal plane): Saccades showed frequent hypometria and some increase in latency to the left, but smooth pursuit was normal at both sides, just slighly saccadic at high frequencies.
VNG hypometric saccades
MRI showed left medullary infarction and also diffuse hemosiderin deposit at left cerebellar hemisphere

Lateral medullary syndrome Lateral medullary infarction

Some comments on a case and advice:
CT scan has NO diagnostic value in evaluating patients with AVS.
Here’s the patient with AVS and risk factors for stroke.
Head impulse test wasn’t done at emergency unit.
Ny on a first day was mimicking Ny of peripheral origin, but it should be very suspicions not to have it on a second day!
Pronounced truncal ataxia is not characteristic for peripheral lesion.
Head impulse test can be positive in central lesions (stroke) as well, because ear get’s blood supply from AICA (sometimes PICA).
Gaze evoked Ny especially with torsional component should bring suspicion to central lesion.
Slight headache can be seen in patients with vestibular neuritis as well, but it’s more characteristic sign of central pathology, especially when it is pronounced.
Fully developed and pronounced neurological signs of Wallenberg syndrome like it is described in textbooks you would not see in the clinical practice.

INO – Internuclear ophtalmoplegia

Internuclear ophtalmoplegia (INO) results from the damage of the MLF (medial longitudinal fasciculus).
INO MLFThe eye on the lesional side can’t adduct during horizontal eye movements. That results in dubble vision when looking contralesionaly. But contruary to III nerve paresis, the eye can adduct during convergence eye movement.

The most frequent cause of INO are stroke and MS.
Here’s an interesting work on INO recording eye movements: LINK