Characteristically, the paralyzed muscles are flaccid in the first days or weeks following a stroke; the tendon reflexes are usually unchanged but may be slightly increased or decreased. Gradually spasticity develops, and the tendon reflexes become brisker. The arm tends to assume a flexed adducted posture and the leg an extended one. Function is rarely if ever restored after the slow evolution of spasticity; however, the use of botulinum toxin may help considerably in relieving the spasticity. Conversely, the early development of spasticity in the arm or the early appearance of a grasp reflex may presage a favorable outcome. In some patients with extensive temporoparietal lesions, the hemiplegia remains flaccid; the arm dangles and the slack leg must be braced to stand. The physiologic explanation of this remains obscure. If the internal capsule is not interrupted completely in a stroke that involves the lenticular nucleus or thalamus, the paralysis may give way to hemichoreoathetosis, hemitremor, or hemiataxia, depending on the particular anatomy of the lesion. Bowel and bladder control usually returns; sphincteric disorders persist in only a few cases. Physical therapy should be initiated early in order to prevent pseudocontracture of muscles and capsulitis at the shoulder, elbow, wrist, knuckles, knee, and ankle. These are frequent complications and often a source of pain and added disability, particularly of the shoulder. Occasionally, atrophy of bone and pain in the hand may accompany the shoulder pain (shoulder–hand syndrome). An annoying dizziness and unsteadiness often persists after damage to the vestibular system in brainstem infarcts.
Seizures are a relatively uncommon sequel of thrombotic strokes in comparison to embolic cortical infarcts, which have been followed by seizures in up to 10 percent of patients in some report, far fewer in our experience. The EEG in these cases of seizure does not normalize, even months after the stroke, and shows sharp activity over the region of the infarct (see further on for treatment of seizures after stroke).
Many patients complain of fatigability and are depressed, possibly more so after strokes that involve the left frontal lobe (Starkstein et al); other studies implicate an infarct on either side of the brain. The explanation of these symptoms is uncertain; some are certainly expressions of a reactive depression. Several small series have suggested that prophylactic treatment with antidepressants reduce the incidence of depression as described in the review by Chen and colleagues, but the routine administration of these medications has not found its way into general practice. Only a few patients develop serious behavior problems or are psychotic after a stroke, but paranoid trends, confusion, stubbornness, and peevishness may appear, or an apathetic state ensues. Large lesions affect concentration as well as synthetic and executive mental functions in rough proportion to their size; these global mental changes are independent of any disturbances in language function.
When multiple infarcts occur over a period of months or years, special types of dementia and gait failure may develop. In some, the major lesions involve the white matter and spare, relatively, the cortex and basal ganglia; the lesions may be lacunar or larger infarctions. This disorder, referred to in the past as arteriosclerotic dementia and Binswanger subcortical leukoencephalopathy, probably represents the accumulation of multiple white matter infarcts and lacunes (see further on and Babikian and Ropper). The white matter that is destroyed tends to lie in the border zones between the penetrating cortical and basal ganglionic arteries. Large patches of subcortical myelin loss and gliosis, in combination with small cortical and subcortical infarcts, are evident with brain imaging. This process and the histologically similar but biologically unique inherited condition of white matter termed CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarct and leukoencephalopathy) are discussed further on.