Occipital Lobes—Lesions of the calcarine area give rise to hemianopsia, and bicortical involvements lead to cortical blindness. Bilateral lesions of the lateral surface may cause mind blindness.
Disturbances in the centrum ovale may cause monoplegias or monoanesthesias, and lesions in the corpus callosum, apraxic symptoms. Characteristic of cerebellar lesions are ataxias and disturbances of equilibrium, often with vertigo and paroxysmal vomiting.
An involvement of the corpora quadrigemina may cause pupillary changes, unilateral or bilateral paralysis of eye muscles, nystagmus, visual disturbances, deafness and ataxia or anesthesia.
Lesions of the cerebral peduncles may give rise to very characteristic syndromes. If the tegmentum and pes pedunculi (basis pedunculi) are both involved, there may be a complete hemiplegia of the opposite side with an oculomotor paralysis on the same side (Weber-Gubler syndrome). Or there may be in addition to this a marked tremor in the limbs of the paralyzed side (Benedikt's syndrome). A unilateral oculomotor paralysis may be combined with a cerebellar ataxia (Nothnagel's syndrome). The thalmic syndrome of Déjerine and Roussy shows a contralateral hemianesthesia, violent and persistent pains on the anesthetic side, hemiataxia, hemichorea or hemiathetosis, slight temporary hemiparesis and sometimes hyperesthesia. Lesions further back, possibly involving the internal capsule, may cause hemianesthesia of touch, pain and temperature senses.
S. A. K. Wilson in 1912 called attention to a particularly important syndrome, designated by him as "progressive lenticular degeneration" and characterized by dysarthria, dysphagia, general tremors of the extremities, forced laughing and crying, muscular rigidities and contractures, with a slight intellectual impairment. Interesting features of this disease complex are that it is familial in type, but not hereditary, comes on early in life, usually progressing to a fatal termination, and is associated with a cirrhosis of the liver which is not alcoholic in origin. At autopsy degenerations of the nucleus lentiformis have been found. J. Ramsey Hunt in 1916 called attention to the association of both paralysis agitans and Huntington's chorea with lesions in the globus pallidus. Oppenheim has recently differentiated a striatum syndrome to which he gave the name "dystonia musculorum." Difficulties in writing, tremors, disturbance of the gait, rigidities, tonic and clonic movements of the muscles and other neurological symptoms are present. Several cases reported by Abrahamson in 1920 showed definite emotional disturbances. Cecile and Oskar Vogt have recently (1919) studied the striatum lesions from a standpoint of both pathology and symptomatology. As summarized by Lhermitte[166] their work shows that athetosis, paralysis agitans, Huntington's chorea, dystonia musculorum, probably paralysis agitans and various other neurological syndromes are to be attributed directly to conditions involving the striate bodies. Prominent among these are softenings and hemorrhages which may result from arteriosclerosis. In view of these facts a careful study of the focal lesions associated with the arteriosclerotic disorders is exceedingly important.
The pathological processes involved have been carefully studied by Heubner and others. He was originally of the opinion that cerebral arteriosclerosis was always of specific origin. Baumgarten, however, subsequently showed that this was not the case. The more characteristic changes in the larger vessels manifest themselves in the form of patches of atheromatous thickening so common at autopsy. As a result of degenerative changes in the elastica and media, and a consequent weakening of the vessel wall, intimal thickening takes place. This is not the circular, uniform, concentric involvement found in syphilitic processes but a localized proliferation of the intima at some one point. There may be an infiltration of colloid and calcareous material in the media. This leads to further intimal thickening. In the smaller vessels arteriocapillary fibrosis has been described—a uniform thickening of the vessel walls with a connective tissue formation. Endarteritis obliterans, first described by Friedländer in 1876, is probably always of syphilitic origin.
In addition to the vascular changes in the cerebral vessels Kraepelin[167] finds usually atheromatous changes in the aorta and its branches, particularly the coronaries, with ulcerations or calcareous plates, hypertrophy and dilatation of the heart, myocarditis, interstitial nephritis and infarctions of various organs. At autopsy the dura and pia are usually thickened and adherent, with a general atrophy of the cerebral convolutions. There are often fresh hemorrhages under the membranes as well as cyst formations and dilatation of the brain ventricles. He particularly emphasizes a splitting of the elastica in the larger cerebral vessels with a thickening and tortuosity, fatty infiltration and calcareous deposits. Hyaline degeneration is common in the elastica and muscularis with fatty granular cells in the adventitia. Capillary aneurysms are often found. Glia proliferation is to be expected in the surrounding area. A condition described by Alzheimer as perivascular gliosis often occurs. There is a disappearance of the perivascular nervous elements with consequent proliferation of the neuroglia. In a general way Kraepelin differentiates several distinct pathological groups—a diffuse cortical involvement, circumscribed processes in the neighborhood of vessels, hemorrhages and softenings. There is also a loss of nerve fibres which are replaced by neuroglia. Binswanger has described a "chronic subcortical encephalitis" due to arteriosclerosis. This consists of an atrophy of the white matter due to an involvement of the deeper marrow vessels. Large gaps and lacunae are found in the course of the vessels. There is an extensive atrophy of the fibres and there may be occasional foci of softening. As a general rule involvement of the large vessels is liable to affect the medullary substance while sclerosis of the smaller vessels leads to cortical disturbances. It is also possible to have extensive lesions without mental symptoms and well developed psychoses with only a slight physical basis. The site of the damage to the vessels determines this. On the other hand, the mental condition may be due to cardiovascular complications resulting usually in anxiety psychoses. The symptomatology may be complicated by senility, alcoholism or syphilis.
Clinically Kraepelin[168] divides the arteriosclerotic psychoses into deteriorations, or milder forms of mental enfeeblement, dementias, depressions, excitements, late epilepsies, and apoplectic dementia. In the milder forms there is a gradual change in the entire psychic personality, with a later development of more marked changes, either physical, mental or both. The early symptoms are a general reduction of the mental capacity and an impairment of memory. The patient tires easily and loses all evidences of energy, with no inclination to undertake anything new. Familiar names and dates are forgotten. Recent occurrences are particularly lost to memory. The real is confused with the false. In business the patient becomes careless and unreliable, overlooks important transactions and forgets appointments. There are often subjective feelings of impending illness. The mood becomes depressed, whining and tearful. Irritability and outbursts of anger occasionally appear, characterized by a marked emotional instability, varying rapidly from tears to laughter. Suicidal tendencies are sometimes noted. Mild confusional states may be induced by alcoholic indulgences. Early physical symptoms are headache, sensations of fulness and pressure in the head, followed by a feeling of dizziness, fatigue, exhaustion, debility, etc. Sooner or later, following a seizure of some kind, neurological signs appear—drooping of the mouth, lateral deviation of the tongue, weakness of an arm, dragging of one leg, loss of sensation on one side, ankle clonus, an increase, decrease or inequality of the patellar reflexes, and sometimes a Babinski reflex. The pupils are very likely to be unequal and sluggish in reaction. The features present a tired, sleepy expression and speech becomes tremulous and monotonous. There may be a difficulty in finding words, or the misuse of words. There are usually tremors of the fingers and movements are uncertain, the gait being unsteady. Romberg's symptom may be present. Dizzy spells and fainting attacks also occur, sometimes followed by genuine convulsions. Apoplectiform seizures may be observed, with unconsciousness for hours or days. These may be followed by sensory or motor aphasia, unilateral paralysis with or without disturbances of sensation, hemianopsia, alexia, agraphia, asymbolism or apraxia. Cardiac disturbances with anxieties are often complications. These apoplectiform and other severe attacks sometimes occur a long time after mental symptoms have appeared. They are likely to recur, mental deterioration progressing rapidly with the repetition of the seizures.
Apprehension is much disturbed and memory weakened, in the advanced cases of deterioration. The patients cannot remember anything for more than a short time. They become disoriented as to time, place and person and forget their own names. Genuine "confabulation" sometimes appears. There are often confusional and delirious states. The mood is frequently depressed or anxious, sometimes irritable or quarrelsome and at times humorous. There is a group of cases showing genuine depressions, usually with hypochondriacal delusions, sometimes with delusions of persecution, self-accusation, and ideas of sinfulness. Even delusions of grandeur are observed. Hallucinations are not infrequent in these cases. States of excitement may intervene with occasional delusions and confused attacks. These excitements are usually of the agitated, restless type, sometimes with suicidal inclinations. Stuporous or even cataleptic states may follow. In the highest forms of excitement sensory or motor aphasia may develop, often with speech disturbances, sometimes of a genuine scanning type. Paraphasias are common. The writing is ataxic or paragraphic. Ideational or motor apraxia often is a symptom. Cyanoses and other evidences of general arteriosclerotic involvement appear. There may be an albuminuric retinitis. Albumen and sometimes sugar appear in the urine. The radials and temporals are thickened or hardened and cardiac murmurs are often found. Blood pressure is greatly increased in many instances, although Romberg found it in only ten per cent of his cases. Sleep is usually interfered with to a marked degree.
In a certain number of the more advanced cases of arteriosclerosis late epilepsies appear. The attacks usually begin between the forty-fifth and sixty-fifth years. There may be fainting spells or genuine convulsions recurring at frequent intervals. These may be associated with brief periods of delirium or may even occur without loss of consciousness. Forgetfulness and mental enfeeblement soon appear in such cases. They also show physical changes with tremors, disturbed reflexes, paralyses, increased blood pressure, etc. Alcoholism seems to be a strongly predisposing factor in this form of arteriosclerotic disorder. Kraepelin found that the epileptic attacks almost invariably appeared in cases which showed a previous history of alcoholic excesses.