Patient 1. A 56-year-old man had experienced recurrent attacks of spinning sensation and nausea for a period of three months. Initially the vertigo had developed when he turned his head to the right while driving. His vertigo lasted only a few seconds and did not accompany tinnitus, hearing loss, or other neurological symptoms. He had hypertension and hypercholesterolemia and was taking 25 mg atenolol and 10 mg atorvastatin per day. At admission his blood pressure was 180/100 mmHg.
A rightward head rotation while either sitting or lying down reproducibly elicited vertigo and nystagmus with a latency of a few seconds. The nystagmus was mainly downbeating, and then after several seconds, it became upbeating even when this rotation was maintained (video 1). The vertical nystagmus usually accompanied horizontal and torsional components. On turning his head back to the neutral position, the vertigo and nystagmus disappeared immediately with a transient reversal of the nystagmus. These attacks were not accompanied by tinnitus, hearing loss, or other neurological abnormalities. Leftward head turning while either sitting or lying down, both Hallpike maneuvers, straight head hanging, and head extension and bending down while sitting did not evoke the vertigo or nystagmus. Other aspects of his neurological examination were normal, as were the audiologic evaluation, bithermal caloric tests, and testing of the subjective visual vertical. He had elevated serum cholesterol at 257 mg/dL. MRI showed mild small vessel ischemic changes in the periventricular white matters. Cerebral angiography in the neutral position showed an aplastic right VA. The left VA was normal. Dynamic angiography documented occlusion of left VA at the C1-2 level when he turned his head to the right (figure 1A). No collateral supply from the anterior circulation was evident.
He underwent C1-2 vertebral body fusion using sublaminar wiring and bone graft. The postoperative course was uneventful and no further attacks of vertigo occurred.
Patient 2. A 70-year-old woman was admitted due to recurrent attacks of dizziness with nausea over a period of several years. She had suffered from Alzheimer’s disease for many years and her cognitive impairments did not permit detailed description of the nature of her vertigo and provoking situations. Her medical history included hypertension, diabetes mellitus, and a previous small thalamic hemorrhage.
She had taken glimepiride 1 mg, metformin 1000 mg, cilostazol 50 mg, donepezil 10 mg, and aspirin 100 mg daily.
In this patient, a rightward head rotation while sitting or lying down repeatedly gave rise to vertigo and nystagmus, which were accompanied by tinnitus in the left ear.
The nystagmus was mainly downbeating with counterclockwise torsional and left horizontal components, and the tinnitus developed several seconds after the onset of nystagmus and vertigo. All these ceased within 15 to 20 seconds even if the rotated head posture was maintained (video 2). Other positional changes did not evoke nystagmus or vertigo.
Other neurotological and laboratory findings were normal except for an elevated blood glucose at 143 mg/dL. MRI showed multiple ischemic lesions in both periventricular white matters and MR angiography showed moderate to severe stenoses of both middle cerebral, both anterior cerebral, left posterior cerebral, and both VAs.
Cerebral angiography showed distal luminal narrowings in both VAs and moderate stenoses of intracranial arteries with meningeal collaterals. Dynamic angiography documented compression of the left VA at the C1-2 level during rightward head turning
(figure 1B).
Patient 3. A-57-year old man presented with a 7-month history of recurrent spinning sensation and ataxia. The vertigo mainly developed when he extended and turned his head to the left, and immediately resolved on resuming the neutral head position. He reported tinnitus in both ears during the attacks, but denied nausea or vomiting. He had a history of diabetes, hypertension, hypercholesterolemia, and had received surgery due to lumbar spondylosis.
On examination, a leftward head rotation while either sitting or lying down induced vertigo and nystagmus with a latency of several seconds. Mild extension of the head during the head rotation elicited the vertigo and nystagmus more easily. The nystagmus was initially downward, rightward, and clockwise, and reversed its direction after 12 seconds, even if the rotated head position was maintained. The reversed nystagmus lasted several seconds after he resumed the neutral head position. He also reported tinnitus during the attacks in the right or both ears. The tinnitus usually developed several seconds after the onset of the vertigo and nystagmus. And, immediate retrial of the head rotation induced either no or a diminished response, and some time was required to reproduce an attack. Other findings of the neurological examination were normal. MRI showed multiple small vessel ischemic lesions in the periventricular white matters. Cerebral angiography showed a normal right VA, however, the left VA was not visualized. During leftward head rotation, the right VA was compressed at the
C1-2 level, and this resulted resulting in a near arrest of the blood flow in the posterior circulation (figure 1C). The patient refused surgery and was placed on Aspirin 100 mg per day with follow-up loss 4 months later.
Patient 4. A 73-year-old woman was referred for the evaluation of intermittent dizziness of several years duration. The dizziness was sometimes spinning, mainly induced by head turning to the left and immediately resolved on returning to the neutral position. The dizziness usually developed when she was tired. The patient had a history of hypertension.
On examination, a leftward head rotation, while either sitting or lying down, was found to elicit vertigo and nystagmus with a latency of three seconds. The nystagmus was downward, rightward, and clockwise, and reversed in direction spontaneously or on resuming the neutral head position (video 3, Fig. 7). She reported tinnitus in the right ear on returning to neutral head position. After repeated trials, the intensity of the vertigo and nystagmus diminished. MRI showed diffuse small vessel ischemic changes in the periventricular white matters. Cerebral angiography documented normal right VA, and an occluded left VA with stenosis at the take off portion. During leftward head rotation, the lumen of the right VA was severely compressed at the C1-2 level. The patient refused surgery and reported intermittent dizziness with head rotation with Aspirin 100 mg twice a day.