An Analytical Biography of a Great Mind- by Edward J. Kempf

Diagnosis of cerebral lesion

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

The kick on the forehead over the left eye evidently fractured the skull at the point of impact and must have violently snapped the head and neck backward. The size and depth of the depression is evidence of its severity. It is most likely that a subdural hemorrhage of considerable size developed here, besides points of hemorrhage elsewhere. The left frontal lobe was certainly damaged, which, in a right-handed, right-eyed person, would have modifying after-effects on his personality, which will be considered later.

The evident, permanent weakness of conjugate movements of the left eye, with tendency to turn slightly upward and outward, and weakness in tonus of the left facial muscles, constitutes a symptom complex that cannot be satisfactorily explained by a single area of permanent brain injury. The lifelong discordance of functioning of the laryngeal muscles is also indicative of additional involvement of involitional nervous action, as is also his daily mental distractibility and moody frustration, as will be seen in many later chapters.

Hydrostatic repercussion within the skull on the opposite side might have, damaged (by shock, if not by another subdural hemorrhage) the right cerebral-cortex in the middle area of the precentral gyrus, supplying motor impulses to the left eye, eyelid, face and pharynx. Penfield and Rasmussen (1950) state that elimination of the precentral gyrus below the arm area produces temporary paralysis of the opposite side of the face, which recovers leaving a residual minor weakness of the lower part only. It sometimes also interferes with mastication and pharyngeal movement and speaking, but functional recovery to normal generally follows here also. Since the facial muscles on both sides have bilateral cortical innervation, the effects of such an injury in a boy would probably have been largely compensated for within a few months, hence more permanent damage probably occurred in some other area.

Several small hemorrhages in the brainstem would have produced the particular permanent ocular and facial effects. If one partly damaged the nucleus of the left fourth nerve to the superior oblique muscle, so as to weaken it, the left eye would then tend continuously to turn more or less upward and outward, as shown in many of Lincoln's photographs, while leaving some degree of volitional coordination. If another point of hemorrhage damaged the nucleus of the left seventh nerve, the left facial muscles would be permanently weakened, likewise with some retention of volitional control. Persistent laryngeal tensions, producing a rasping, high pitched voice, might have also followed from another petechial hemorrhage that impaired vagus innervation.

The 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 deliberately, always with the intention of expressing himself simply and directly so as to be clearly understood. However, he spoke in a slow staccato monotone, indicating deficiency in sense of inflection, a serious impairment in a public speaker.

Frontal lobe impairment on the left side (of a right-eyed and right-handed person) of the corticothalamic system of integration of nervous interactions would have reduced the egoistic volitional production of conscious visual imagery of self-in-its-environment, requiring compensatory development of the right corticothalamic connections to serve this indispensable function. More stimulation than in normal people would then be necessary in order to remain mentally acutely active. A person with such a cerebral lesion would have, in order to keep his mind working at a highly attentive sensory discriminating level, to keep himself involved in emotionally stimulating situations by cultivating exciting social interests and objectives. As will be seen in later chapters, Lincoln did just this, constantly, through his passion for realistic accuracy and simplicity of reasoning, truth, directness, honesty, kindness and friendliness of self-expression, and upholding the equalitarian moral and legal rights of all people, cultivating a moralizing sense of humor, and challenging illegally exercised political and judicial authority.

The most significant of his symptoms was the repetitive tendency, when not being stimulated by environmental activities to lapse automatically into a lower conscious state of mental detachment, tending to sadness and gloominess, with characteristic facial expression. This was described by some of his friends as "ugly and stupid looking" and others as "dull," "sad and abstract," "detached" and "withdrawn." When a man in his forties, he told his friends that he was never without "melancholy." Upon being stimulated in a way that aroused emotivating interest, such as some incident or some interpersonal talk, his facial expression was observed to change quickly from dull indifference to animated interest, with a tendency to smile and laugh.

As a humorist telling moral stories of frustrated vanities and a humanist seeking freedom and peace of mind for all people as well as himself, he carried on endlessly to overcome his subconscious tendency to lapse into a rut of sad, gloomy, visual, mental preoccupation over the fateful futility of life. He also intentionally cultivated special forms of self-stimulation in habits of reading aloud to himself and other people, memorizing, and writing out his reasonings. By reading aloud, he told Herndon, he gained the benefit of hearing as well as seeing what he read, enabling him thereby to remember more easily. By writing out his reasons for and against making decisions he formed stable convictions.

Records of descriptions of Lincoln's physical and personal disabilities as a boy and man, by himself and neighbors and friends, are numerous, many of which are presented in later chapters. The earliest is that of Josiah Crawford in Gentryville, Ind. He employed the boy Lincoln, loaned him books for study and liked to jest him about the way he "stuck out" his lower lip, apparently regarding it as a boy's eccentric habit. When Lincoln returned to southern Indiana in 1844, age 35, to make a speech, his lower lip still protruded abnormally. When Crawford asked him about his books for making the speech, Lincoln, remembering his joking, replied humorously, "I haven't any. Sticking out my lip is all I need." Tarbell (1924) who has retold the story, saw in it evidence that "this habit, fallen into in youth, resulted in that protruberance of the lower lip which is a distinguishing characteristic of his face," an interpretation held generally by his medical and lay biographers.

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