The field of movement disorders is relatively broad, encompassing disorders of increased
movement, such as tremors, dystonia, and tics, to disorders characterized by a
paucity of movement, such as Parkinson’s disease. Our understanding of the pathogenic
mechanisms and our treatment options are expanding at a rapid pace. This expansion
ranges from the medical and surgical advances in treating Parkinson’s disease to the flood
of genetic abnormalities that have now been found to cause various movement disorders.
Mắt bại liên hợp - supranuclear palsies ảnh hưởng đến sự phối hợp chứ không phải là cơ -
yếu đuối. Không có khả năng nhìn theo hướng cụ thể, thường trở lên intranuclear tổn thương: hội tụ bình thường nhưng có thể không phải là mắt adduct trên cái nhìn bên
Some patients maintain tone in antigravity muscles but fall over like a tree trunk, as if postural defenses had disengaged. There may be a consistent direction to such falls. The patient with cerebellar pathology may lean and topple over toward the side of the lesion. Patients with lesions of the vestibular system or its central pathways may experience lateral pulsion and toppling falls. Patients with progressive supranuclear palsy often fall over backwards. Falls of this nature occur in patients with advanced Parkinson's disease once postural instability has developed.
Parkinsonism and Freezing Gait
Parkinson's disease (Chap. 366) is common, affecting 1% of the population 55. The stooped posture and shuffling gait are characteristic and distinctive features. Patients sometimes accelerate (festinate) with walking or display retropulsion. There may be difficulty with gait initiation (freezing) and a tendency to turn en bloc. Imbalance and falls may develop as the disease progresses over years.
Parinaud's Syndrome Also known as dorsal midbrain syndrome, this is a distinct supranuclear vertical gaze disorder from damage to the posterior commissure. It is a classic sign of hydrocephalus from aqueductal stenosis. Pineal region tumors, cysticercosis, and stroke also cause Parinaud's syndrome. Features include loss of upgaze (and sometimes downgaze), convergence-retraction nystagmus on attempted upgaze, downwards ocular deviation ("setting sun" sign), lid retraction (Collier's sign), skew deviation, pseudoabducens palsy, and light-near dissociation of the pupils.