Nervous System Involvement in Behcet’s Disease
It is a well known fact that those who suffer from Behcet disease may also suffer certain types of neurological medical problems which may be related in an indirect or direct manner. The most common ones, which are usually considered as direct effects of Behcet disease include a non structural recurrent vascular type headaches and cerebral venous sinus thrombosis. Those who considered to be related to the Behcet disease in an indirect manner include neurologic complications, depression and tension type headache. Some rare cases of Behcet disease may also include certain peripheral nervous system involvements. Other involvements related to the nervous system may include coincidental neurological involvement, secondary neurological involvement, complications of treatment of Behcet disease and Neuro-psycho-Behcet syndrome.
Diagnostic Criteria for Neuro-Behcet Syndrome
There are certain criteria which need to be fulfilled so that the neuro-Behcet syndrome can be diagnosed properly. First of all, the International Diagnostic Criteria for Behcet’s disease needs to be fulfilled. A person needs to suffer from certain neurological symptoms which cannot be associated with any other type of neurological or systemic disease. The person who is about to be diagnosed with Neuro-Behcet syndrome also needs to show at least one of the following: abnormal neurophysiological studies which are always in consistence with the current neurological symptoms, abnormal cerebrospinal fluid findings suggestive of Neuro-Behcet syndrome, abnormal neuroimaging findings suggestive of Neuro-Behcet syndrome or objective abnormalities on neurological examination. As already explained, the two major neurological presentations of Behcet’s disease are the cerebral venous sinus thrombosis or the central nervous system involvement. The cerebral venous sinus thrombosis is commonly related to an increased intracranial pressure, while the central nervous system involvement usually includes certain cortiospinal tract syndromes or brainstem syndromes. Cerebral venous sinus thrombosis is also referred to as extra axial NBS, while the central nervous system involvement may also be referred to as intra axial NBS.
Diagnosis of “Headache” in Patients with Behcet’s Disease
There are various types of different headaches which can be diagnosed in persons who suffer from Behcet’s disease. They include co-existing primary headaches such as tension type headaches or migraines, the non structural headaches of Behcet’s disease, headaches in associated with ocular inflammations, headaches due to cerebral venous sinus thrombosis and headaches due to central nervous system parenchymal involvement. Headaches are actually the most common neurological symptoms among people who suffer from Behcet’s disease. There are cases of Behcet’s syndrome which are characterized by a paroxysmal migraine like headaches which may be frontal or bilateral and their throbbing and severity may vary from person to person. These headaches usually occur when all other systemic symptoms of Behcet’s disease start kicking as well. There are also certain cases which may be associated with rather severe headaches, and all of them usually require further evaluation.
According to certain statistical data from the Behcet’s Disease Research Center the range of patients affected by nervous system involvement in Behcet’s disease is somewhere between 2.2 and 49 percent. The reported mean age of onset of Behcet’s disease is 26.7, while the reported mean age of onset for nervous system involvement associated with Behcet’s disease is 32 years. It is a peculiar fact that various different types of neurological complications associated with Behcet’s disease affect male patients much more often than they affect female patients. The ratio of male to female patients with Behcet’s disease is somewhere around 3.8 to 1, while the ration of male to female patients whose condition is accompanied by nervous system involvement is somewhere around 1.8 to 1. The male predominance is also noted in cases of other sorts of vascular complications of Behcet’s disease.
Intra-axial NBS and Extra-axial NBS
Intra-axial NBS involves the onset of certain subacute brainstem syndrome which is commonly characterized by mild confusion, unilateral or bilateral corticospinal tract signs, dysarthria and cranial nerve findings. It is very rare to find any cases of NBS which are not accompanied by oral ulcers. A peculiar fact is that not all intra-axial NBS cases involve brainstem symptoms and signs. Some less common cases of intra-axial NBS may also involve extrapiramidal seizures and signs, a progressive or self limited myelopathy, emotional lability, cognitive-behavioral changes and hemiparesis. Various sorts of voiding dysfunctions which affect the sphincteric components and the bladder may also be present in some cases. There are approximately 15 percent of cases of Behcet’s disease which are accompanied by cerebral venous sinus thrombosis as a neurologic involvement. This involvement may be characterized by certain symptoms such as moderate headaches, motor ocular cranial nerve palsies, mental changes and in some cases even severe headaches. This type of thrombosis never occurs suddenly as it takes some time to develop fully. Some cases with cerebral venous sinus thrombosis may be accompanied by severe symptoms such as hemiparesis, sixth nerve paresis, papilledema, focal neurologic signs, coma, paralysis and convulsions.