OVERVIEW
Stiff Person Syndrome is a rare and severe central nervous system disorder characterized by excessive muscle contraction of the trunk axis and lower extremities with myalgic muscle spasms. A variety of high-titer autoantibodies can be detected in patients with other autoimmune diseases. Clinical manifestations commonly include persistent or fluctuating stiffness of the trunk, limbs, and neck muscles, plate-like firmness of the abdominal muscles, and simultaneous involvement of the active and antagonistic muscles. Benzodiazepines are currently the drugs of choice for the treatment of this disease. The prognosis for this disease is good if there are no complications.
Questions you may be concerned about
What does stiff person syndrome sps mean
SPS stands for stiff person syndrome, a disease of the central nervous system. The etiology includes genetic factors, neurophysiology, and others. It manifests as paroxysmal muscle pain in the abdomen, trunk and other parts of the body, with gradual onset of muscle stiffness and other symptoms.
It is a central nervous system disease characterized by excessive muscle contraction of the trunk and lower limbs, accompanied by muscle pain and muscle spasm. The etiology of the disease is considered to be related to genetic factors, neurophysiology, and immune response.
In the early stage of the disease, there are paroxysmal muscle pains in the abdomen, trunk and other parts of the body, which may involve the limbs and trunk, etc. The progression of the disease will result in persistent or fluctuating muscle stiffness, and the joint activities are obviously limited. Sometimes a slight stimulus can induce severe pain, severe pain in the limbs, panic and screaming.
After the onset of the disease under the guidance of the doctor to symptomatic treatment.
Causes
The cause of this disease may be related to genetics, neurophysiology, immune response, etc..
1. Although the cause of the disease is unclear, the continuous excitation of spinal motor neurons and the elevated level of norepinephrine metabolites in the urine of the patient suggest that the imbalance between the excitation and inhibition of the GABA inhibitory system and the norepinephrine system of the central nervous system may be the cause of the symptoms of the disease.
2. In recent years, a number of studies have suggested that patients with this disease have positive clonal bands in the cerebrospinal cord and increased lgG synthesis. This may be related to immunologic abnormalities, but remains to be confirmed.
Symptoms
Stiff person syndrome has an insidious onset, often chronic and fluctuating, there is often a history of infection before the disease, and the duration of the disease ranges from 5 days to 4 months. Initially, paroxysmal soreness in the abdomen, trunk, and muscles with tightness, non-specific and transient, followed by involvement of the extremities. With the progression of the disease, persistent or fluctuating stiffness of the trunk, limbs and neck muscles is common, abdominal muscles are plate-like or stone-like firmness, and active and antagonistic muscles are involved at the same time. The joints are fixed, with limited random activities, and in severe cases, the joints are fixed in a stiff-man-like posture, with the masticatory muscles being the most common in the country, followed by the cervical muscles in the first instance. In addition to muscle stiffness and dyskinesia, a few may be accompanied by cone-bundle sign. Symptoms progress, followed by lumbar muscles, neck muscles, trunk muscles and proximal muscles of the limbs tightness, stiffness, limitation of voluntary activities, walking straight and can not bend over, etc., but the stiffness disappears after sleep.
Paroxysmal pain produces spasms and provoking factors, a little stimulation can induce painful limbs and lumbar muscles painful spasms, passive movement or sudden emotional stimulation can be induced. Seizure of the patient’s severe pain, crying, panic, loud howling, sweating, arrhythmia, etc., severe cases can lead to fractures or muscle tears. It rarely involves facial expression muscles and pharyngeal muscles. On neurological examination, there is no abnormal finding except for muscle tonus, and intelligence is normal. A few patients have dysphagia, respiratory muscle involvement, tension of the sternocleidomastoid muscle, and some have emotional disorders such as depression, insomnia, hallucinations and delusions.
Examination
1. Electromyography
The resting potentials show persistent normal action potentials, which suddenly increase during spontaneous spasms after somatosensory stimulation or passive movements. EMG activity is attenuated or absent after sleep or sedation with diazepam, general or spinal anesthesia, nufluralcaine, or argyrophilic block. Chewing is increased due to increased central excitability and sympathetic activity.
2. Muscle biopsy
The muscle biopsy is usually normal, and individual can see mild hyaline-like degeneration of muscle fiber.
3. Electroencephalogram
Usually normal.
4. Cerebrospinal fluid examination
The cell count may be normal, with a few cases of mild elevation of protein or immunoglobulin lgG, lgA, lgM.
5. Blood test
Autoimmune antibodies can be detected.
6. Head CT and MRI examination
Most of the patients have no abnormalities, and head CT shows small calcified foci. In some patients, MRI of the head may show transient inflammatory changes or atrophy of the brainstem or high cervical medulla.
7. Other
There may be increased urinary creatine excretion, but it is a nonspecific change.
Diagnosis
According to the clinical features of the disease, the diagnostic criteria are as follows:
1. Persistent stiffness and ankylosis of the axial muscles (including the facial muscles and masticatory muscles) with a “plate-like” appearance (proximal limb muscles may be involved);
2. Abnormal body-axis posture (often with excessive lumbar lordosis);
3. sudden painful spasms, caused by random movements, emotional distress, or unanticipated auditory and somatosensory stimuli, which are relieved or disappear after sleep;
4. persistent motor unit activity (CMUA) in at least one body axis machine;
5. EMG resting potentials may have normal action potential emission, enhanced EMG emission during seizures, and diminished or disappeared potential emission after injection of valium;
6. Treatment with Valium-type drugs is effective;
7. Metastases due to tumor should be excluded.
Differential diagnosis
This disease should be differentiated from the following diseases:
1. tetanus
Valium-type drugs are effective in this disease, while tetanus is ineffective. The EEG is normal in this disease, while about 50% of EEGs are abnormal in tetanus.
2. Differentiate from congenital myotonia.
This disease is characterized by continued contraction of the transverse striatum muscle even after the cessation of movement, myoclonic response to percussion, typical myotonia on EMG, effective with procainamide.
3. Isacs-Mertens syndrome (i.e., myasthenia gravis – dwarfism – diffuse bone disease)
The disease presents with extensive myotonia, with involvement mostly in the eyes and face. Patients usually have short stature, bone deformities and peculiar facial features, and respond well to phenytoin sodium. Electromyography shows sustained motor neuron potentials during muscle rest.
4. Organophosphorus pesticide poisoning
Patients have a history of pesticide exposure, early pesticide poisoning may or may not have a reaction, the majority of patients with muscle fascicular tremor, the individual appeared to be plate-like muscle tonus, with the invalidity of Valium, with atropine and dephosphorylated drugs have a special effect.
5. This disease should also be differentiated from hysteria, polymyositis, extrapyramidal diseases, pseudo-muscular ankylosis and arthritis, cervical spondylosis and so on.
Complications
The disease is often complicated by severe episodic autonomic dysfunction, such as fear, pain, loud howling, profuse sweating, shortness of breath, tachycardia, pupil dilatation, elevated blood pressure, and elevated body temperature. Generalized diffuse muscle rigidity is common.
Treatment
1. Benzodiazepines
It is the drug of choice for the treatment of this disease. Valium is widely used, which can realize its muscle relaxation effect by increasing the presynaptic inhibition in the spinal cord caused by GABA. The dosage varies from person to person, and the dosage will be reduced by 20mg per day after the improvement to the discontinuation of the drug.
2. Clonidine
Clonidine can be taken orally or intravenously, and is very effective. Individual serious patients may die due to asphyxia or respiratory or cardiac arrest.
3.10% chloral hydrate enema
Satisfactory results can be achieved, but not yet reported.
4.SMS is an autoimmune disease
Treatment of the disease with immunosuppressants (intravenous cyclophosphamide), corticosteroids, intravenous immunoglobulin or plasma exchange therapy is effective.
5. Intrathecal baclofen is given to patients with SMS.
It may reduce rigidity and spasticity. Baclofen is a GA derivative, which can inhibit the transmission between monosynaptic and polysynaptic neurons in the spinal cord, and it also has inhibitory effect on the high central nervous system, and it has significant muscle relaxation effect.
6. Traditional Chinese Medicine (TCM)
Traditional Chinese medicine believes that this disease is caused by body weakness and sweating, fluid depletion, tendons and veins are not moistened, it is appropriate to and camp to solve the muscle, soothe the Xiangqiang, through the meridians to activate the genus, and activate the blood to eliminate siltation treatment.
Prevention
Prevent respiratory and urinary tract infections, avoid sound and light stimuli, maintain emotional stability, and prevent various triggering factors.