THE FRIDAY NOON CONFERENCE

A case of Horseshoe shaped commissure syndrome

Naresh Mullaguri MDDepartment of Neurology

University of Missouri

\\\ Chief complaint \\\

• Slurred speech, dysphagia and difficulty walking

History of present illness

• 53 year old RH white male presented to the VA ER with the chief complaint of 2 day history of slurring of speech, double vision and difficulty walking.

• He had a prior history of brainstem stroke in 2012 which residual left sided weakness and ambulates well with the help of a cane at baseline. He is from Arizona and came to Missouri to visit his mother. He was watching TV at her home in the evening when this happened suddenly and he waited at home for 2 days thinking that the spell will resolve but it got worse to the point that he can barely stand without support, choke on food and water and everything started to appear double on the left side of the space.

• He continued to take plavix since his prior Stroke and denied having such symptoms since his old stroke. Also felt subjectively more weak on the left side.

• Denied any nausea, vomiting, headache, facial pain, fever, chills, neck pain or stiffness, trauma, bowel or bladder incontinence, weight loss, appetite loss

HPI continued• Double vision: He closes his left eye throughout the interview to

focus on my face. Doesn’t need to do that if the subject of interest is on the right side. Complained of difficulty swallowing as often he has nasal regurgitation and coughing with food. Gets worse if he tries to eat and talk.

• He mentioned that he feels very imbalanced when standing and mentioned that he had to stand with a very wide base and had to move sideways and almost afraid to walk forward without support. He denied any spinning sensation but mentioned that his upper body seems like disconnected from his lower body to hold the weight. For the past 2 days he confined mostly to bed because of that and his mother suggested that he seek medical attention.

SUPPORTING HISTORY• Past medical History: HTN, DM, HLD, OSA, Old Brainstem

Infarct• Past surgical History: Left knee replacement, Tonsillectomy• Social History: Lives in Arizona, on Long-term disability from

prior stroke and used to work as a chef in the army. Lot of travel history to middle east and European countries while on service.

• No good habits • Family History: Lung cancer• Allergies: No known drug allergies

ExaminationVitals: Temp: 36.4, HR: 91, BP: 155/95 mm of Hg, RR: 14General: Alert, awake and oriented X 4, no distress, lying down on the ER gurney with left eye closedEye: Dysconjugate gaze, left eye up beating nystagmus, horizontal nystagmus is elicited in all the directions. Right sided internuclear ophthalmoplegia. Pupils are 4mm, round and reacting to light bilaterally, Fundoscopic exam showed sharp optic discs, good cup to disc ratio, no peripheral retinal lesions. No ptosis, congestion of the eyes, increased watering of the eyes. No RAPD.HENT: normocephalic, atraumatic with moist oral mucosa. No oral lesions, rhythmic jerking of the soft palate not halted by saying “aaahhh…..”

Medications

• Amlodipine• Atenolol• Plavix• Gabapentin• Lantus• Losartan• Metformin• Spiranolactone• Ibuprofen

Physical examination continued….• Neck: supple, non-tender, no jugular venous distension, full range

of motion• Respiratory: Clear to auscultation bilaterally, symmetrical chest

wall expansion• Cardiovascular: Regular rate, sinus rhythm, no murmer, distal

pulses palpable. No edema• Gastrointestinal: soft• Musculoskeletal: Normal range of motion, No tenderness, No

swelling• Integumentary: No rash, warm, pink, no pallor or icterus• Psychiatric: Cooperative, slightly impaired insight but appropriate

Neurological examination• Higher mental functions: memory is intact to recent and remote events, attention and

concentration are good, Speech is dysarthric and at times anarthric, He holds his mandible against the maxilla to produce clear speech and he can also produce clear speech by talking during forced expiration, No astereognosis or agraphesthesia, No inattention or extinction, Language and comprehension are intact. He followed multistep commands.

• Cranial Nerve exam: visual fields are full to confrontation, Right medial rectus palsy but gets better when checking the accommodation, No facial sensory loss or asymmetry, Corneal reflexes intact bilaterally, jaw strength is normal including the medial and lateral pterygoids. Palatal Myoclonus +, SCM is 5/5 and Tongue protrudes to midline with no atrophy or fasciculation.

• Motor system: Bulk is normal bilaterally, slightly increased tone on the left upper and lower extremity with no spasticity or rigidity, left hand grip is weak but otherwise 5/5 bilaterally in the upper and lower extremities. Couldn’t stand without support and stands with a wide base and prefers to walk sideways and very unsteady when he tried to walk ahead. DTRs were 2+/4 in bilateral biceps, triceps, brachioradialis, knees and ankles. Plantars were down going bilaterally.

• Sensory system: Intact to light touch, temperature, pinprick. vibration is diminished in bilateral lower extremities left more than right. Romberg’s sign not assessed.

• Coordination: grossly intact to FTN in bilateral upper extremities. Dysdiadochokinesia bilaterally left worse than right, HTS ataxic on the left side. Severe truncal ataxia when he stood up

Differential diagnosis

1. Midbrain Lacunar infarct2. Acute demyelinating lesion of the

Midbrain3. Mass with compression on the

midbrain

Labs

• TEG showed 31 % inhibition and 91% for ASA• LDL – 178• A1c – 7.6• WBC count – 14.8

Imaging studies

• MRI showed right caudal Midbrain/Rostral pons infarct which is acute with old right medulla lacunar infarct

• CTA of the Head and Neck showed occluded right vertebral artery before joining the Basilar artery with a sessile aneurysm of 7mmX7mm at the basilar artery tip

Localization

Caudal Midbrain Lacunar infarctaka

Wernekinck’s Commissure syndrome

Features of the syndrome• Bilateral cerebellar dysfunction + Occasional Occulomotor

signs like INO + Palatal tremor

Wernekinck commissure the decussation of the brachia conjunctiva before  their entrance into  the red nucleus of the  tegmentum.Wernekinck decussation  the decussation of the left and right superior  Cerebellar peduncle

Discussion• Wernekinck’s syndrome was first reported by Lhermitte in 1958, only a few cases have been reported.• The commissure is located anterior t0 the Aqueduct and at the paramedian region of the caudal

midbrain.• In the caudal midbrain and rostral pons it is the only anatomical structure responsible for bilateral

ataxia.• All the cases showed severe ataxia and dysarthria which are consistent findings• Oculomotor signs can be variable, at the same time it is rare to have INO.• The vestibulo-ocular examination showed 2/3 of the cases (total of 10) showed Nystagmus mostly

upbeating when looked upwards, well known sign caused by lesion in the midbrain/brachium conjunctivum. Not been reported in Wernekinck’s syndrome before.

• Delayed palatal Myoclonus with inferior olivary nucleus degeneration has been reported. It can happen at various time intervals.

• Etiology was due to occlusion of the penetrating artery caused by insitu atherosclerosis or artery to artery embolism based on the vertebral artery focal stenosis

Thank you