The study of 3H leucine incorporation into skeletal muscle of mouse muscular dystrophy (129 ReJ/dy Bar Harbour strain) shows the uptake of isotope into myofibrils. The techniques employed were light and EM autoradiography before and after glycerination (Szent-Gyorgyi 1947). The results indicate a marked drop in uptake of the 3H-Leucine into myofibrils in the dystrophic animals, supporting the contention of Nihei et al (1971) that reduced myosin synthesis occurs in mouse muscular dystrophy.

Electrophysiological studies have been carried out on five patients with neuropathies of different etiologies. In each patient serial estimates were made of the numbers of functioning motor units in various muscles. It was found that the intensity of the neuropathic process and the rate of recovery differed in a consistent way among the motoneuron pools investigated. The lesion was more severe in extensor digitorum brevis neurons than in thenar neurons, while the hypothenar ones were least affected. A stage of partial synaptic failure has been recognized in which a motoneuron appears to be no longer able to excite a muscle fiber, but still capable of maintaining certain trophic activities. By comparing the number of functioning motor units with the size of the maximum evoked muscle response it has been possible to detect the adoption of denervated muscle fibers by axonal sprouts from ‘healthy’ surviving neurons (collateral reinnervation). Lastly, in some muscles it appears that the adopted muscle fibers may subsequently be recaptured by the original motoneurons following recovery of the latter from the neurotoxic insult.

The aim of this experiment was to investigate the reaction of peripheral nerve tissue to a synthetic absorbable suture material. Polyglycolic acid suture material was placed within the sciatic nerve of rats and the absorption of the material was investigated by means of electron photomicrographs. It was concluded that placement of polyglycolic acid into the peculiar environment of endoneurial tissues results in minimal scarring and in minimal disturbance of the surrounding nerve fibers. The material was progressively absorbed with minimal disturbance of intrafascicular structures.

Since the description by Galen in the 2nd Century, A.D., clinical neurology has acknowledged the existence of two types of tremor: that which occurs at rest and that occuring during the execution of movement. With the help of refined methods of analysis, E.M.G. and cinephotography, the authors have carried out a detailed clinical assessment in more than 400 patients.

The basic criterion used to define a tremor was the classical definition of Dejerine: “An involuntary, rhythmical and symmetrical movement about an axis of equilibrium.”

As a result of this study, the conclusion has been reached that there are two types of tremor: postural tremor and tremor of attitude. Both are present while the limb remains immobile, whether by wilful design or when at rest in a position of posture and subject only to the action of gravity.

During voluntary movement, tremor is not present. Irregular, asymmetrical and non-rhythmic oscillations may appear however — as in so-called intention tremor, of cerebellar origin — but this abnormal movement can hardly be called a real tremor. It is merely a manifestation of ataxia.

As a consequence of this study, it is suggested that further understanding of the basic mechanism of tremor can be reached by the investigation of the central neural structures which are involved in the physiology of posture and attitude.

Thirty-nine patients with a variety of diseases, including essential tremor, Parkinsonߣs Disease, olivopontocerebellar degeneration, ataxia telangiectasia, and cervical cord injury with action tremor, were evaluated for the effect of one ounce of absolute alcohol ingestion. Tremor significantly subsided in 61.9% of E.T.; 46.6% of P.D.; one patient with A.T.; and one patient with C6 lesion. The tremor became worse in one patient with O.P.C.D. Twenty of these patients were treated with propranolol, an average dose of 92 mgm. per day, and re-evaluated three to six months later. All those who improved on alcohol improved on propranolol and the one whose tremor accentuated with alcohol had a similar response to propranolol. It is concluded that the tremorilytic effect of alcohol is neither specific for, nor limited to, essential tremor and is of no value in differentiating various neurological disorders which manifest as action tremor. It is recommended that one ounce of absolute alcohol by mouth be used as an office procedure to predict the response of patientsߣ tremor to propranolol.

Ten patients have been described showing inability to stop breathing on command, spontaneous respiration and voluntary respiratory stimulation being unaffected. This abnormality not previously described in the literature, we feel should be named respiratory inhibitory apraxia (R.I.A.). The anatomical organization of respiration is briefly reviewed. R.I.A. is often associated with other forms of apraxia or motor impersistence. It is thought that the urinary and bowel incontinence present in some of these cases might also represent a form of inhibitory apraxia. Information is presented which supports the view that respiratory inhibitory apraxia is due to a minor hemisphere lesion, usually deepseated. Our one autopsied case showed a lesion in the descending motor pathways in the internal capsule, in middle cerebral artery branch territory, disconnecting the voluntary respiratory inhibitory center in the cortex in anterior and middle cerebral cortical branch territories.

Median eminence and ventromedial hypothalamus have in the past been the principal foci of research in neuroendocrine and neurovisceral control mechanisms. The present report provides an overview of work involving the dorsomedial hypothalamic nucleus (DMN). This structure is located dorsal to the ventromedial hypothalamic nucleus (VMN) and extends anteroposteriorly from the plane of the largest cross section of the VMN to the plane of the dorsal premammillary nucleus. Fibers from the DMN pass with the periventricular system and the dorsal longitudinal fasciculus of Schütz and have been traced to the midbrain tegmentum and reticular formation. Intrahypothalamic connections involve intensive networks between DMN, lateral hypothalamic nucleus (LHN) and VMN. Regarding neurotransmitters, recent studies indicate that the DMN receives noradrenergic innervation along two pathways, a dorsal and a ventral one. Monoamine-containing systems approach the DMN from the lateral hypothalamus and the bulk of these fibers are carried in the medium forebrain bundle from their cells of origin in the brain stem. Studies of the vascular supply indicate that both VMN and DMN receive their blood supply from the internal carotid artery. It has been recently demonstrated that the DMN is involved in the control of food intake and possibly water intake as well. Discrete lesions in the DMN have caused hypophagia and hypodipsia, and implantation of epinephrine and norepinephrine in this area has initiated eating. Many years ago, electrical stimulation of this area was reported to cause eating. Although DMN lesions cause hypodipsia, they do not result in the reduced water/food intake ratios that are so characteristic of the VMN syndrome. DMN lesions are also followed by reduced spontaneous activity (running wheel), but this reduced activity is not accompanied by increased weight gain and accretion of adipose tissue, the latter being consistently observed in the VMN rat. Rather, carcass fat remains normal in the DMN rat and carcass protein is either normal or slightly increased. Many of the aforementioned changes in weanling rats with DMN lesions, however, are not matched by similar alterations in the intermediary metabolism of carbohydrate and lipid. Possibly this is due to a “resetting” of a central autonomic control system that makes it possible for the DMN rat to adapt more efficiently to a reduced influx of substrate, i.e. the consistent hypophagia. From a review of the literature it appears that the DMN and their circuitry are involved in only a few neuroendocrine, i.e. hypothalamohypophyseal control mechanisms. Both lesion and cervical stimulation experiments suggest an involvement of the DMN in the control of LTH. Circumstantial evidence points to the DMN as a possible formation and/or storage site of growth hormone inhibiting factor (GIF). Although DMN rats show reduced ponderal and linear growth, they have been found to have normal or elevated plasma growth hormone (GH) levels. Both lesion and stimulation studies have yielded the impression that the DMN is not involved in thyroid, i.e., thyrotropin stimulating hormone releasing factor (TSHRF) control. Electrical stimulation of the DMN has been reported to result in a positive correlation between adrenal blood flow and adrenal corticoid release in hypophysectomized dogs. This has been interpreted as a coordinated response at the level of a “dorsomedial sympathetic vasodilator relay” rather than a “true” neuroendocrine effect via corticotropin releasing factor (CRF). Experiments that failed to demonstrate a relationship between the DMN and the tonic and cyclic control of luteinizing hormone releasing factor (LHRF) are discussed. The data reviewed indicate the existence in the dorsomedial hypothalamus of an area that exerts a profound influence on many aspects of neurovisceral and some neuroendocrine control systems.

The field potentials recorded simultaneously at various depth of the rabbit’s visual cortex and superior colliculus were analysed following light ON and light OFF. The collicular ON and OFF potentials exhibited three slow components superimposed by fast rhythmic oscillations. Only the first slow component reversed its polarity with penetration from surface negative to positive in depth. The cortical ON and OFF responses similarly contained three slow waves which all reversed their polarity with electrode penetration: from surface positive to negative in deeper layers. The most striking difference between ON and OFF cortical responses is the absence of fast rhythmic oscillations in the cortical ON response.

Skin punch biopsies and huffy coats of white blood cells were examined electron microscopically in patients suffering from a variety of storage diseases. No specific abnormalities could be detected in Gaucher’s disease and adrenoleucodystrophy. While characteristic deposits were found in cutaneous nerves in globoid and metachromatic leucodystrophy, this method was deemed inferior to sural nerve biopsy. In gangliosidoses, on the other hand, pathognomonic membranous cytoplasmic bodies were common in axons of cutaneous nerves, and in generalized gangliosidoses marked vacuolation of many other cells was prominent. Specific deposits were found in various cells in skin punch biopsies and in lymphocytes of children suffering from ceroid lipofuscinoses, and in lymphocytes of their parents. This constitutes the easiest diagnostic laboratory procedure in such cases.

This is a report of the first recorded instance of ventricular obstruction at the foramen of Monro by an ectatic carotid artery. The clinical course, investigations and treatment are described.