The cerebellum, a unique brain structure with distinctly organized neuronal circuits, is critical for motor and cognitive functions. The cerebellum has dense neuronal connections with almost all regions of the cerebral cortex and brainstem, and can serve as a “hub”…
Dizziness is a term patients use to describe a variety of symptoms including spinning or movement of the environment (vertigo), lightheadedness, presyncope, or imbalance. Patients may also use the term for other sensations such as visual distortion, internal spinning, nonspecific…
Other chapters in this book that deal with symptoms emphasize history as the starting point for generating possibilities for the differential diagnosis. This list of diagnostic considerations is then refined during the examination. This chapter calls for a different approach.…
Headache is an exceedingly common symptom that affects virtually everyone at some time in life. It is estimated that nearly half of the world’s adults have an active headache disorder ( ). Headache is one of the most common reasons…
Disorders of smell and taste can jeopardize human safety and produce loss of appetite, unintended weight loss, malnutrition, occupational disability, and reduced quality of life. In a study of 750 patients with chemosensory disturbances, 68% reported altered quality of life,…
General Principles of Ocular Motor Control I do not know of any kind of work better fitted for correcting loose habits of observation and careless thinking than a study of the ocular motor nerves. John Hughlings Jackson, 1877 This chapter…
Pupillary Abnormalities Pupil Anatomy and Neural Control The size of the pupil is determined by the balance of action between two muscles embedded in the iris: the sphincter pupillae, under parasympathetic control, and the dilator pupillae, under sympathetic control. The…
Afferent Visual System Anatomy and Physiology From a conceptual standpoint, it is useful to consider vision as having two components: central or macular vision (high acuity, color perception, and light-adapted) and peripheral or ambulatory vision (low acuity, poor color perception,…
The mechanics of swallowing are like those of an elegant wristwatch. On the surface, this appears to be a simple, perhaps even pedestrian process, but it is actually both tremendously complex and remarkably fascinating. Humans swallow approximately 500 times daily…
Motor Speech Disorders Motor speech disorders are syndromes of abnormal articulation, the motor production of speech, without abnormalities of language. A patient with a motor speech disorder should be able to produce normal expressive language in writing and to comprehend…