by Edward J. Kempf, M.D. Wading River, N.Y.

Tentative Diagnosis of Nature of Cerebral Injury

Although modern neurology requires for diagnosis a far more complete examination of the living subject for positive or negative evidence of nervous impairment, a tentative consideration of several types of injury to the brain that might have produced the unusual complex of symptoms in Lincoln's case, as far as is known, is desirable.

The blow on the forehead over the left eye evidently fractured the skull at the point of impact. The size and depth of the depression are evidence of its severity. It is most likely that a subdural hematoma of considerable size and petechial hemorrhages developed. The left frontal lobe was certainly damaged, which, in a right-handed, right-eyed person, would possibly have some modifying after-effects on the personality. These will be considered later.

The evident, permanent weakness of conjugate movements of the left eye, with the tendency of the eye to turn slightly upward and outward, and the weakness in tonus of the left facial muscles constitute a symptom complex that cannot be satisfactorily explained by a single area of permanent injury to the brain. The lifelong hypertension of the muscles of the pharynx and/or larynx is also indicative of involvement of autonomic nervous action, as are also his daily repetitive moodiness and emotional instability.

Hydrostatic repercussion within the skull on the opposite side (contrecoup) might have damaged, by shock or limited subdural hemorrhage, the right cerebral cortex in the lower frontoparietal area, where the weakened muscles have motor representation close together in a small area. But since the facial muscles have bilateral cortical representation, the effects of such an injury in a boy would have been completely compensated for within a few weeks; hence permanent damage must have occurred in some other area.

Several small hemorrhages in the midbrain or brain stem might have produced the particular permanent ocular and facial effects. If the nucleus of the left third cranial nerve supplying the interior rectus muscle were partly damaged, so as to weaken this muscle, the left eye would then tend continuously to turn more or less upward and slightly outward, as shown in Lincoln’s photograph, while some degree of volitional coordination would be left. If another spot of hemorrhage damaged the nucleus of the left seventh cranial nerve, the facial muscles on that side would have been permanently weakened. If a third spot touched a certain portion of the midbrain, disturbance of sympathetic nervous action with permanent vocal tension might have followed.

Such weakening of the left facial muscles would probably have only minor secondary effects on the personality.

The production of a high-pitched, rasping voice was more important, but Lincoln largely overcame this professional deficiency by speaking thoughtfully, slowly, and clearly, always with the common-sense intention of expressing himself directly in the simplest words and thoughts that fitted the subject.

Decoordination of the left eye was more serious in that it tended to produce diplopia and severe eyestrain, which was increased upon fatigue or emotional excitement, with the sequelae of headache, nausea, indigestion, and depression. The deformation of facial expression and stress of diplopia required the development of the mental counter defenses and compensations, which characterized his personality.

Lincoln had other symptoms of permanent nervous lesions. With his rasping, high-pitched, nervous voice, he spoke in a slow, staccato monotone, indicating deficiency in sense of inflection in a public speaker, who naturally would have greatly desired this ability.

But most significant of all the symptoms was the repetitive tendency to lapse automatically into a lower conscious state, of mental detachment or abstraction, with characteristic facial expression, described by some of his friends as "ugly and stupid-looking," and by others as "dull," or "sad and abstract." or "detached," or "withdrawn." He told his friends, when a man in the 40’s, that he was never without "melancholy." Upon being stimulated by his environment in a way that aroused autonomic-affective reactions of interest, as by some incident or some person's talk, or by reading, his facial expression was observed to change quickly from dull indifference to animated interest, with the tendency to smile and laugh. Herndon, his law partner, said he would sometimes burst out laughing to himself without apparent cause.

Several men and women friends (Mary Owens, W. H. Herndon, L. Swett, and Mrs. Lincoln) saw in him an unusual lack of appreciation of beauty, nicety, and refinement and an inordinate fondness for laughing over vulgar, witty stories with clever, practical, or moral application. In contrast to this kind of aesthetic lapse, he was extremely fond of certain beautiful qualities of prose and poetry and memorized many passages from the Bible, Shakespeare, Burns, Gray, Goldsmith, and other poets. Most of all, he was highly conscientious about being truthful, reliable, honest, kind, fair, just, and loyal. His sense of fitness in the clarity, and logic of his statements, his discrimination of innocence and guilt, truth and deception and justice in the courtroom, and his sense of definition and appropriateness in his speeches, were masterly. These aesthetic contrasts, of deficiency in some respects and of supremacy in others, might have been the effects of cultural preference more than of cerebral capacity.

The continuous tendency to lapse into melancholy or gloomy "blues" was, however, probably consistent with a permanent, cerebrally initiated, schizoid tendency to lapse automatically into a mentally dull, detached, drowsy state, and then to react, upon interpersonal stimulation, with excessive euphoric compensations.

This inhibitory-reaction tendency was also relatively overcome by the culture of certain forms of self-excitation, such as reading aloud to himself or other people, telling humorous stories, and becoming particularly adept in engaging in legal fights for justice. He liked to read aloud, he said to Herndon, {10} for thereby he gained the benefit of hearing, as well as seeing, what he read and remembered it more easily.

Two different loci of cerebral injury might have produced the complex volitional mental instabilities with the unstable sympathetic nervous reactions under stress or fatigue. One such locus would be a subcortical disruption (thalamic-sensory or hypothalamic-motor) at the head of the autonomic nervous system that depressed sympathetic nervous action and tended to produce dullness or drowsiness upon lack of excitatory stimulation. The other would be an impairment of the frontal cortex on the left side (of a right-eyed and right-handed person), involving the corticothalamic cycle of nerve impulses, that reduced the volitional production of the conscious stream of visual imagery of self-in-its-environment, so that such a person would require more external stimulation than would a normal one in order to remain mentally attentive. A person with this type of cerebral lesion, in order to keep mentally alert, would have to be involved, or keep himself involved, in emotionally stimulating situations by cultivating special stimulating interests and objectives, such as a passion for legal justice for all people. Lincoln did just this, as a humorist seeking happiness and as a humanist seeking justice, in an endless fight to overcome the tendency to lapse into a rut of sad, gloomy, suicidal preoccupations.

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