What Is Neurosarcoidosis?

Sarcoidosis, also known as sarcoidosis, is a chronic granulomatous disease of unknown cause that can invade multiple organs throughout the body, with the highest incidence of lung and lymph nodes. About 5% of sarcoidosis patients invade the nervous system and show signs of neurological damage, known as sarcoidosis. Nervous system sarcoidosis can recur, and according to statistics, about one-third of the patients may have recurrent episodes.

Basic Information

Visiting department

Neurology

Common symptoms

Headache, vomiting, stiff neck or seizures, etc.

Contagious

no

Clinical manifestations of sarcoidosis in the nervous system

Onset is usually slow, and the severity of neurological damage is related to the activity of nodular granuloma, the location and extent of the lesion.

Brain damage

Sarcoidosis of the nervous system mainly involves the meninges, parameninges, parenchyma, hypothalamus and pituitary.

(1) Meningeal lesions are mainly manifested by chronic meningitis, and patients show headache, vomiting, neck rigidity or seizures.

(2) Most skull nerve damage can be found in skull base arachnoid involvement.

(3) Meningeal involvement is often accompanied by damage to the hypothalamus pituitary, which can include diabetes insipidus, autonomic dysfunction, and abnormal levels of prolactin.

(4) Brain parenchymal damage is also more common, with periventricular and ependymal involvement as the main manifestation of single or multiple nodular granulomas. Patients often have headache and vomiting, optic disc edema, hemiplegia, hemi blind aphasia, and multiple Granulomatous damage can cause ventricular membrane involvement in dementia, often with hydrocephalus.

(5) There are fewer cases of intracranial tumors, which can be similar to meningiomas and gliomas.

(6) There may be damage to the brainstem and cerebellum.

(7) Stroke-like manifestations are rare in patients with sarcoidosis of the nervous system.

Spinal cord injury

Rarely, spinal cord lesions of the sarcoidosis of the nervous system are mostly subacute or chronic, with local granulomatous infiltration and local occupying being more common. The clinical manifestations are low back pain, leg pain, weakness, decreased or missing sensation, paraplegia, Defecation disorders and so on.

3. Peripheral nerve damage

In patients with sarcoidosis in the nervous system, spinal nerve involvement is the most common and can be manifested as neurological damage such as mononeuritis polyradiculopathy, Guillain-Barre syndrome, and symmetric polyneuropathy. Facial nerve damage is more common and can be expressed as For peripheral facial paralysis, hearing impairment, visual impairment and eye movement disorders.

4. Muscle system damage

It has been reported that the muscle damage in this disease is characterized by signs of granulomatous polymyositis. Clinically, it may be asymptomatic or manifested as muscle weakness, muscle atrophy, myalgia, and muscle nodules, with trunk muscles and proximal muscle damage mainly.

Sarcoidosis of the nervous system

Laboratory inspection

(1) Lumbar puncture CSF examination often shows that the number of abnormal white blood cells is significantly increased, mainly lymphocytes, and the protein content is increased. About 20% of patients have reduced CSF sugar content. The IgG index in CSF can sometimes increase, with or without oligoclonal bands. Angiotensin I converting enzyme (SACE) is elevated in most CSF.

(2) The serum angiotensin converting enzyme is significantly increased, which is of high value in the diagnosis and judgment of the activity of sarcoidosis of the nervous system, but it is not unique to this disease. Other diseases such as multiple sclerosis Guillain -Barre syndrome, Behcet syndrome, and neurological degenerative diseases can also increase, but it is not as obvious as sarcoidosis.

2. Other auxiliary inspections

(1) Electromyography The changes of peripheral nerve damage can be found. Most of them show mild to moderate sensation and reduced motor conduction velocity. The amplitude of mixed muscle action potentials and sensory nerve action potentials can be reduced normally or mildly to moderately.

(2) Cerebral angiography is mostly normal, with only occasional manifestations of vasculitis. Brain CT often shows a slight increase in the density of the lesion area, and the lesion is uniformly strengthened after contrast agent enhancement, and edema bands may appear around it. MRI has a high sensitivity for the diagnosis of sarcoidosis of the nervous system. It can show that there is a T ₂ weighted high signal change in the white matter around the ventricle. The T ₁ weighted image shows multiple signals. When meningeal lesions are mixed, enhanced scans can find meningeal enhancement. .

(3) The radioactive nuclide ⁶⁷ gallium ( ⁶⁷ Ga) scan is of high diagnostic value for sarcoidosis and can detect lung lesions early. Some scholars believe that the combination of ⁶⁷ Ga scan and serum angiotensin I converting enzyme can diagnose sarcoidosis with an accuracy of 80% to 90%.

Biopsy of the meninges and brain tissue or peripheral nerves can confirm the diagnosis.

Diagnosis of sarcoidosis of the nervous system

The diagnosis of sarcoidosis of the nervous system is not difficult if it appears on the basis of systemic sarcoidosis. If it is the sole manifestation of sarcoidosis or sarcoidosis granuloma first invades the nervous system, it often causes misdiagnosis. If there are unexplained symptoms of central nervous system, peripheral nervous and muscular system damage, and endocrine dysfunction, there is no other reason to explain it, especially in young adult patients, the clinical possibility of sarcoidosis should be highly suspected, such as With a history of skin, lymph nodes, and lung nodules, the possibility of this disease should be considered. Biopsy of the meninges and brain tissue or peripheral nerves can confirm the diagnosis.

Differential diagnosis of sarcoidosis in the nervous system

It should be distinguished from other chronic aseptic meningitis, intracranial space-occupying lesions, cerebral parasitic disease and cerebral swine cysticercosis (cysticercosis).

Nervous System Sarcoidosis Treatment

Most patients with sarcoidosis of the nervous system can be relieved by prolonged treatment with adrenal corticosteroids. Some scholars have suggested that the average duration of prednisone treatment is 60 months, and that the central nervous system lesions are chronically progressive or repeated. The author may add cyclophosphamide drugs or low-dose whole brain radiation therapy. Recurrence and relapse are common in patients with hydrocephalus or patients with prednisone with a small dose and a short course of treatment. Cyclosporine and prednisone are currently recommended. The dose of prednisone is reduced to 30% to 50% of the original dose. %, Can be well controlled and reduce the side effects of hormones.

Prognosis of sarcoidosis in the nervous system

Patients with sarcoidosis of the nervous system are often prone to relapse, and they are slowly exacerbated and have a poor prognosis. If there is a brain mass, hydrocephalus and intracranial lesions associated with epilepsy have a poor prognosis. Therefore, early diagnosis and early treatment can significantly alleviate the condition, and a small dose of hormone maintenance should be given during the remission period of the disease, which may improve the prognosis.