1/4. Mal de debarquement presenting in the Emergency Department.Mal de debarquement (MDD) is a common, benign, and self-limited syndrome suffered by many people after disembarkation from an oceangoing vessel. It is characterized by a continuing sensation of being on an unsteady pitching and rolling deck, even after a return to solid ground. Symptoms typically dissipate over several hours or days, but can linger for weeks. There is no effective treatment for MDD, no work-up is required, and patients can be reassured that the symptoms are transient. We present a case of MDD in a previously healthy 22-year-old male, and discuss the approach to MDD in the emergency department setting.- - - - - - - - - - ranking = 1keywords = vessel (Clic here for more details about this article) |
2/4. Remote cerebral hemisphere symptoms from surgically treated patients with posterior fossa brain tumors; vascular factors: a basis for a theory concerning space sickness.Three case histories of patients with large tumors in the posterior fossa who were operated on in a sitting position subsequently developed 1 or more symptoms referable to the temporoparietooccipital regions of the brain 24 to 48 hours postoperatively. Initially, it was believed that such symptoms were due to a stimulation of the association pathways causing firing of remote association areas (See Ch. 4). Subsequent studies of the rotation of blood vessels of the brain in the developing embryo and a review of the anatomical location of the arteries supplying the temporoparietooccipital region led to the conclusion that some compromise of the posterior cerebral artery was responsible for the symptoms. The symptomatology in these brain tumor patients was not unlike that seen in the cosmonauts and astronauts in space flight, designated as "motion sickness" in the space literature. A suggestion was made as to clarification of the definitions. This author advocated that the term "motion sickness" be confined to those symptoms of dizziness, nausea, and vomiting, due to involvement of the peripheral end organ, the inner ear. "Space sickness" might include these symptoms but also might have the addition of disorientation or the inversion of image in space and formed or unformed hallucinations. These relate to the temporoparietooccipital area, the midtemporal, and the occipital regions. In such instances, there must be central involvement or a stimulation of this interpretive cortex of the brain. The remote symptoms from the supratentorial cotex were believed to be due to hypoxia related to the posterior cerebral artery compromise, resulting in delayed "luxury perfusion" and the development of local lactic acidosis. Transaxial transmission of force with an uncal tentorial herniation causing compression of the posterior cerebral artery was suggested as a mechanism responsible for the vascular compression.- - - - - - - - - - ranking = 1keywords = vessel (Clic here for more details about this article) |
3/4. motion sickness: part II--a clinical study based on surgery of cerebral hemisphere lesions.Man has always been intrigued with the localization of function within the brain but has paid insufficient attention to the long and the short association fiber pathways which, when stimulated, may fire distant areas evoking unusual responses. Three cases of intracerebral lesions are presented to demonstrate the significance of these structures. The vestibular symptoms of dizziness may occur from excitation of the temporal operculum. If, added to this symptom, the patient has spatial disorientation, such as feeling upside down, it suggests that the region of the supramarginal gyrus and the angular gyrus are involved. When unformed visual hallucinations (such as flashes of light) or formed hallucinations (such as distorted images) are present the occipital and midtemporal regions of the brain, respectively, are considered to be the sources of such responses. The symptoms described above were reminiscent of those experienced by some of the cosmonauts and astronauts and it called the authors' attention to this "motion sickness in space." The areas from which such responses may be elicited are the temporoparieto-occipital regions, which are nourished by the posterior cerebral artery and its branches. Vascular insufficiency to this area by spasm of the vessel may be responsible for this symptomatology.- - - - - - - - - - ranking = 1keywords = vessel (Clic here for more details about this article) |
4/4. Clinical features of mal de debarquement: adaptation and habituation to sea conditions.A survey conducted among 116 crew members of seagoing vessels confirmed that mal de debarquement (M-D) is a transient feeling of swinging, swaying, unsteadiness, and disequilibrium. None of the subjects requested medical attention, although there were isolated cases in which a strong sensation of swinging and unsteadiness caused transient postural instability and impaired the ability to drive. In most cases, the sensation of M-D appeared immediately on disembarking and generally lasted a few hours. In addition, subjects usually described bouts or attacks of M-D associated with changes in body posture, head position, or with closing of the eyes. M-D was reported by 72% of our subjects. Sixty-six percent of subjects reported a high incidence following their first voyages. A significant positive correlation was found between M-D and seasickness susceptibility. The nature of M-D may be explained within the framework of multisensorimotor adaptation and habituation to a new or abnormal motion environment. It is suggested that M-D represents a dynamic, multisensorimotor form of CNS adaptive plasticity.- - - - - - - - - - ranking = 1keywords = vessel (Clic here for more details about this article) |