8,9) Head Impulse * Face the patient * Ask the patient to focus on your nose * Quickly turn the patient's head to one side and then the other * If the patient cannot fixate forward during the test, the test is positive for a peripheral lesion Nystagmus * Horizontal nystagmus: If there is an increase in the intensity of the nystagmus when the patient looks in the direction of the fast phase of the nystagmus, then the test is positive for a peripheral lesion * Vertical or rotary nystagmus is almost always associated with a central lesion
Test of Skew * Face the patient * Ask the patient to focus on your nose * Cover one eye and then the other.
A central lesion
would be more indicative of keratitis, but a peripheral lesion does not exclude keratitis.
This case suggests a possible link of lateral medulla to cluster like headache etiology and further emphasizes that semiology of cluster headache can be secondary to central lesions
You suspect she has a peripheral rather than a central lesion
and could have vestibular neuritis.
This is verified by the appearance of a vesicular or pustular lesion, palpable induration in the area, and a central lesion
that is a crust or an ulcer.
A central lesion
can be suspected in patients with upper motor neuron signs such as positive Babinski's sign, hyperreflexia or clonus.
There are 3 variants of adenomatoid odontogenic tumour, the follicular type (accounting for 73% of cases), which has a central lesion
associated with an embedded tooth; the extrafollicular type (24% of case), which has a central lesion
and no connection with the tooth; and the peripheral variety (3% of cases).
It typically occurs on habitually exposed skin sites as an annular lesion with a subtle depression in the center and "just a smidgeon of epidermal atrophy" in the central lesion
52] In 1863, Gerhardt hypothesized that the different glottic configurations observed were due to lesions at different levels along the nerve, with a bilateral central lesion
causing bilateral abduction or the "cadaver" configuration.