Sarcoidosis and the Nervous System - SarcoidosisUK

SARCOIDOSIS AND THE NERVOUS SYSTEM

Sarcoidosis can occur in almost any organ. In 5 to 15% of patients with sarcoidosis, the disease occurs somewhere in the nervous system. This is called neurosarcoidosis.

Construction of the Nervous System

The nervous system is made up of the central and peripheral nervous system. The brain and spinal cord form the central nervous system. The peripheral nervous system consists of nerves and peripheral nerves in the brain (cranial nerves).

The cranial nerves control the eye muscles, the muscles of the face, tongue and swallowing muscles. The cranial nerves provide the sense of smell, sight, taste, hearing and sense of touch.

Peripheral nerves extend from the spinal cord to the torso, arms and legs and to the internal organs. A special type of peripheral nerve may be referred to as the thin nerve fibers. Sometimes muscles are also included in the peripheral nervous system.

Sarcoidosis in the Nervous System

When inflammation occurs as a result of sarcoidosis, the operation of the nervous system is disturbed at that location. The symptoms are varied and dependent on the affected area in the nervous system. They are summarised (right), alongside additional tests which may be necessary after consulting your doctor.

Signs and Symptoms of Neurosarcoidosis

Sarcoidosis Involvement Signs and Symptoms (may include) Additional Testing (see below)
Hypothalamus and pituitary gland Weight gain, diabetes insipidus, insomnia MRI
Brain Headache, amnesia, focal hemispheric syndromes. MRI, LP, sometimes EEC
Cranial nerves Crooked face, partial blindness, olfactory loss, deafness, face ache (and combinations of these). MRI, LP
Meninges Headache, stiff neck, fever. LP
Body and limbs Spinal gait disturbances, urinary symptoms, balance disorder. MRI, LP
Peripheral 'Different feeling' pain or weakened nerves. EMG
Nerve fibers Pain in the feet, dizziness while standing, palpitations. Sometimes LEP
Muscles Weakness and muscle pain, muscle cramps. EMG, PET

Techniques to Understand your Condition

If your symptoms suggest neurosarcoidosis your doctor will refer you to a neurologist. This doctor will map neurological signs and symptoms. A physical examination is always part of a consultation with a neurologist. If necessary, they will also arrange any additional tests such as:

EEC (Electro Encephalo Gram): measures electrical activity and the function of the brain.

EMG (Electro Myo Gram): examination of the function of peripheral nerves and muscles using electrical impulses and needles.

LEP (Laser Evoked Potentials): measurement of the function of the pain fibers.

LP (Lumbar Puncture): also called epidural - can identify inflammatory cells in the cerebrospinal fluid.

MRI (Magnetic Resonance Image): images sarcoidosis inflammations, making them visible.

PET (Positron Emission Tomography): active sarcoidosis inflammations are made visible.

CFS (Cerebrospinal Fluid Analysis): the pressure and flow of the cerebrospinal fluid is tested. This helps to exclude other potential diagnoses.

Treatment

Neurosarcoidosis can be treated with medication. Often these are corticosteroids (e.g. prednisone) in tablet form.

If this is insufficient or has no effect, a cytotoxic drug is prescribed. Usually, this is methotrexate (together with folic acid). Other medications, for example cyclosporin, azathioprine or infliximab may also be prescribed.

The effect of the treatment is usually noticed after a few months. High doses, which are necessary in some cases for extended periods of time, may unfortunately have little effect.

Neurosurgical intervention is very rarely necessary and only to treat life-threatening complications.

Warning signs…

Severe neurological abnormalities in sarcoidosis are fortunately rare. Headaches are therefore not immediately indicative of neurosarcoidosis.

However, complaints including hemiplegia, paralysis of the face, lurching walk and partial blindness should lead directly to a consultation with your doctor.