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Of the Occipital Lobe* by Morris B J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.20.2.139 on 1 May 1957. Downloaded from J. Neurol. Neurosurg. Psychiat., 1957, 20, 139. DISORDERS OF OCULOMOTOR FUNCTION IN LESIONS OF THE OCCIPITAL LOBE* BY MORRIS B. BENDER, DONALD M. POSTEL, and HOWARD P. KRIEGER From the Departments of Neurology of New York University, Bellevue Medical Centre, and the Mount Sinai Hospital, New York City The physician and even the neurologist associates parietal lobe ". The latter three patients include the occipital lobe with visual functions. Rarely the two in whom eye movements were elicited from does one attribute motor disturbance to lesions in area 19. Penfield similarly accounted for the this region of the brain. While there is no doubt difference between his and Foerster's results by that normal vision is dependent on intactness of noting that the latter used much stronger stimuli the calcarine cortex and the subcortical optic and evoked adversive convulsions including the radiations, there is apparently little clinical evidence eyes. In their work Penfield and his associates in (Penfield and Boldrey, 1937; Penfield and Rasmussen, to indicate that the occipital area plays a role Protected by copyright. the movements of the eyes. From experiments in 1950) did not consider any epileptiform reactions animals and cortical stimulations in man it is as positive results. However, in recent work on apparent that the occipital lobe must have an the monkey with implanted electrodes Lilly and influence on eye movements. his colleagues (1956) have evoked adversion, in- In monkeys various types of eye movements have cluding the eyes, upon stimulation of the lateral been elicited from the occipital cortex and sub- surface of the occipital lobe and not isolated eye cortex (Shafer, 1888; Luciani and Tamburini, 1879; movements. Grunbaum and Sherrington, 1901; Walker and While there are examples of excitatory influences Weaver, 1940; Crosby and Henderson, 1948; Lilly, on eye movements produced by stimulating the Hughes, and Galkin, 1956; Krieger, Wagman, and occipital lobe, there is very little information on Bender, 1955). While these effects are easily oculomotor deficits as a result of lesions in this area. obtained in the alert and less readily in the Gordon Holmes (1921) described defects in visual anaesthetized monkey, ocular deviations are difficult fixation and fusion movements of the eyes in gun- to elicit on electric stimulation of the occipital shot wounds of the occipital lobes. The so-called cortex in man. Walker and Weaver (1940) stated voluntary movements which remain are not perfect. that eye movements can be elicited from the For example, fixation other than straight forward occipital area in all animals but man. Foerster cannot easily be maintained and may be accompanied http://jnnp.bmj.com/ (1931), on the other hand, stated that ocular devia- by nystagmus. These abnormalities are found even tions could be evoked on stimulation of area 19 though there is no paralysis of the individual eye but not areas 18 or 17. Penfield and Boldrey (1937) muscles involved. Thus it is reflex maintenance of reported two cases with contralateral ocular devia- conjugate gaze in any one direction or even centering tion after stimulation of area 19. However, in 1950 of eyes which is defective and the chief complaint Penfield and Rasmussen stated that in 31 patients is usually blurred vision, which increases with any 48 loci for eyeball movement were found and " all movement of the line of vision. This blurred vision were located rostral to the central sulcus ". To persists with one eye closed, thereby differentiating on October 2, 2021 by guest. explain the previous observations the following it from diplopia. Although bilateral occipital lobe footnote is then added: " In earlier operations in damage is usually necessary for this syndrome, which less physiological stimulating currents were reflex maintenance of gaze may be defective uni- used, eye turning was elicited in one patient from laterally. When it is bilateral it becomes even more the temporal lobe and in three patients from the marked. The post-mortem examinations of cases by Gordon Holmes (1921) revealed that this defect in fixation was related to "interruption of the * This work was aided in part by grants No. B-174 (S.D.) and No. B-294(C) from the United States Public Health Service. cortico-tectal fibres which form the efferent link 139 J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.20.2.139 on 1 May 1957. Downloaded from 140 MORRIS B. BENDER, DONALD M. POSTEL, AND HOWARD P. KRIEGER of the reflex arch; the disease involved the dorsal Case 1.-D. G. developed hypertension (160-1701 portion of the thalamus including the pulvinar". 100-110 mm. Hg) at the age of 33. At 37 years of age In addition, Gordon Holmes described occipital he suffered, in rapid succession, a coronary occlusion, lesions as producing paresis of gaze to the side a popliteal thrombus, multiple pulmonary infarcts, and an embolus to the right posterior cerebral artery. The opposite the lesion. In his cases this occurred only latter was followed by an almost congruent left homony- in hemianopics who were mentally obtunded, mous hemianopia, spots before the eyes, and blurred suggesting that what Holmes may have observed is vision. In 1949, at the age of 41, he was completely what has been described as hemispatial inattention blind for one hour. This was followed by left-sided or hemispatial agnosia. Dejerine and Roussy (1905) blindness and the subjective experience of being dragged observed such paresis after a recent occipital injury to the left by the head and eyes. in a previously blind person, suggesting that vision The patient was admitted to the Mount Sinai Hospital is not the factor in these cases. Gordon Holmes for special studies. The visual sensory symptoms and (1921) also noted that many hemianopics could not signs of this patient just after the episode of complete fixate blindness have been reported previously (Bender and accurately targets on the hemianopic side, Kahn, 1949). Essentially, there was an incongruent left despite preservation of macular vision and accurate homonymous hemianopia with scotomas and a small fixation of a target in the midline. Holmes concluded relative scotoma in the right upper quadrants (Fig. 1). that such a defect could not be due to visual loss These defective fields were the site of trouble in per- but was due to unilateral loss of the visual reflexes ception of motion, form, distance, colour and after- needed for maintaining the position of the eyes imagery. Additional signs of neurological disease were achieved by voluntary ocular movement. hyperaesthesia of the left upper lip and right wrist. There In contrast to these observations and deductions was transient evidence of a hemiparesis affecting the are those of Penfield and Rasmussen (1950). They right foot. Radiographs of the skull, the cerebrospinal amputated one occipital lobe and found the only fluid, and an electroencephalogram were normal. The diagnosis was bilateral and successive occlusion of the Protected by copyright. defect to be a contralateral homonymous hemianopia. posterior cerebral arteries. There was no difficulty in oculomotor functions. The most marked oculomotor defect found after the Excision of the occipital cortex outside the calcarine second occlusion was nystagmus on fixation of a target region produced no defect in vision or oculomotor during deviation of the eyes to the side of the maximum function of which the patient was aware. Destruc- field defect (left). The nystagmus was a shimmering, tion of the occipital lobe in monkeys leads to cogwheel type of eye movement apparent on attempted contralateral hemianopia and at most to a transient fixation of a target at the near point. During fixation defect in contralateral conjugate gaze which is at a distance this nystagmus was absent. When present, at a near point, nystagmus was most marked in the associated with turning of the entire body about its fixating right eye, the non-fixating eye being turned long axis in the direction of the side of the inward, giving it the appearance of making a strong lesion. attempt at convergence. Nausea and vertigo developed The present study concerns alterations in oculo- when such fixation was prolonged. motor activity appearing subsequent to lesions of Double vision was experienced during fixation at the the occipital lobes in two patients. near point or at a distance. If the patient looked at his L.E. R.E. http://jnnp.bmj.com/ FIG. I.-Perimetric and tangent (opposite page) screen visual fields of D. G. illumination, daylight; 5 mm. white target at 33 cm. Solid black, absence of perception of motion. Vertical lines, movement per- ceived but marked blurring £067s'' ~~~and fluctuation in appearance on October 2, 2021 by guest. of target. Stippling, target less blurred. Small circles and horizontal dashes, blurred or grey vision. The dashes in the perimetric fields outline the field of vision for the colour red. J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.20.2.139 on 1 May 1957. Downloaded from DISEASES OF OCULOMOTOR FUNCTION 141 " r, , II, , , , . O.Fo . Ise,_R&_ NV sy Ag. 8__ | , v '_tL I 0 d0 ,t' \ _1tS: _srm ts _ S W11,, X X I I I I] -r\xr>iil 11_ s; _--_7 5v '0__?w7I X1tM1\I/1Ds_ m-Ls- ale oll AIA I Y _Y X _ _ v_ , w z mMIZS- -ue - ,_ \ _ _ xl 7 sll- 7_L_ rL1 r I I e. uL ZS T\lL_ZS-Z|l_- W ln - FIG. 1 .. a.es juhr job ass g "O ,JA , AON i A J"_ _ SAsw r _7 _ I L _z Z _ _ - on own finger he saw two parallel fingers one overlying the other.
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