General Information
Diseases in which axons are preserved, oligodendrocytes and myelin are affected
According to the etiopathogenesis, it can be examined in 2 groups as demyelinating and dysmyelinating diseases.
Dysmyelinating Diseases
It is a disorder due to a problem in the genetic coding of myelin. It occurs in childhood.
1. Lysosomal Disorders
2. Peroxisomal Disorders
3. Organic Acid and Amino Acid Metabolism Disorders
4. Myelin Disorders Due to Unknown Metabolic Disorder
Demyelinating Diseases
A. Autoimmune
1- Multiple sclerosis
2- Neuromyelitis optica (Devic's disease)
3-ADEM (acute disseminated encephalopathy)
4- Acute hemorrhagic leukoencephalopathy
B. Infectious
• Progressive multifocal leukoencephalopathy
C. Metabolic / Toxic
• Central pontine myelinosis
• Vitamin B12 deficiency
Multiple Sclerosis
0 It is a recurrent or progressive inflammatory, demyelinating disease of the white matter. It involves different parts of the central nervous system at different times.
0 It is common between the ages of 20-40 and women are affected twice as often.
0 Autoimmunity, genetic predisposition, infection and other environmental causes are blamed in the etiopathogenesis.
Clinic:
1) The most common symptom is sensory complaints. (numbness, tingling, burning)
2) Visual symptoms: Optic neuropathy, retrobulbar neuritis, diplopia
3) Sensory: Temporary numbness
4) Motor: Pyramidal pathway dysfunction is common. It causes muscle weakness (monoparesis, paraparesis), spasticity and increased reflexes. Babinski, clonus (pathological reflexes) may occur. Superficial reflexes are lost. Muscle atrophies may develop due to disuse.
5) Cerebellar: Ataxia, action tremor, dysmetria
6) Genitourinary: Impotence, neurogenic bladder
7) Mental: Cognitive losses
Brain atrophy, enlarged ventricles, and examination of the corpus callosum also indicate cognitive dysfunction.
8) Epileptic seizures may be seen.
Junctional paresthesias - girdle - may occur. It is in the form of a feeling of pressure surrounding the body.
Retained Territories
Periventricular white matter-most common
Optic nerve
Mesencephalon
Pons
Cerebellum
Spinal cord
Clinical tables suggestive of multiple sclerosis
Beginning between the ages of 15-50
Findings of involvement of multiple foci in the CNS
Optic neuropathy (The most common cause of optic neuritis is MS.
Temporal arteritis is the most common cause of optic neuritis aged 70 years and over.
The most common visual field disorder in optic neuritis and optic atrophy is central scotoma.
Lhermitte's sign: Electric shock sensation descending from the vertebrae while the head is flexed.
Internuclear ophthalmoplegia
Fatigue
Worsening with increase in body temperature: Uhtoff sign
Clinical manifestations not suggestive of multiple sclerosis
Before the age of 10, onset after the age of 60
Involvement of the peripheral nervous system
Hemianopsia
Rigidity, fixed dystonia
Cortical findings such as aphasia, apraxia, agnosia, alexia, neglect
Early dementia
Diagnosis:
The best method for diagnosis is MR imaging with contrast.
Shows demyelinating plaques.
Periventricular MS lesions located at right angles to the ependyma on MRI are called Dawson's fingers.
Laboratory in multiple sclerosis:
1) Cerebrospinal fluid
a. Mononuclear pleocytosis (6-20 cells/mm3)
b. Oligoclonal band positivity: It is the most widely used diagnostic method. It may also be positive in syphilis, Lyme, and subacute sclerosing panencephalitis.
c. Protein level is increased or normal. It should be below 100 mg/dl.
D. IG index: higher than 0.7
to. Increase in myelin basic protein ratio
2) Evoked potentials:
Visual, auditory and somatosensory evoked potentials are impaired, slowed down
3) Demyelinated areas are called Shadow plaques in Pathology.
Clinic types
1- Relapsing remitting form (most common)
2- Progressive relapse
3- Primary progressive
4- Secondary progressive
Prognosis criteria
|
good
prognosis |
poor
prognosis |
|
Relapsing remitting form (going with
attacks) |
progressive |
|
Early onset - young age |
late start |
|
optic neuritis symptoms |
cerebellar |
|
Woman |
motor signs |
|
Presence of sensory findings |
sphincter defect |
|
Presence of cranial neuropathy |
pyramidal |
|
|
Male |
Treatment:
• In the acute period: Steroid, plasmapheresis
• In the inactive period: Immunotherapy---glatiramer acetate, azathioprine, cyclophosphamide, beta interferon, alpha interferon (historical), monoclonal antibodies (natalizumab, alemtuzumab, ocrelizumab), fingolimod (used orally), teriflunomide, dimethyl fumarate, mitoxantrone.
- IFN-gamma is not used
Multiple Sclerosis Variants
• Charcot variant: No or very few brain MRI findings, mainly seen as spinal cord syndrome.
• Marburg variant: It progresses with severe deficits and frequent death in two years.
• Balo's concentric sclerosis: In childhood, mass-like lesions (Intracranial hypertension findings)
Devic's Disease (Neuromyelitis Optica)
0 It is a condition in which optic neuritis and transverse myelitis of the spinal cord occur together.
0 Most patients develop bilateral optic neuropathy.
0 NMO-IgG against Aquaporin-4 is positive.
0 Involvement in MR is in optic nerves and medulla spinalis.
ADEM (Acute Disseminated Encephalopathy)
0 Viral disease is a demyelinating disease that can develop after insect bites and vaccination.
0 It is more common in childhood than MS.
0 The disease is in the form of a single attack.
Progressive Multifocal Leukoencephalopathy
It is a demyelinating disease caused by Papova viruses.
0 Occurs in patients with weak cellular immunity. (Immunosuppressant therapy)
0 Demyelination occurs as a result of virus destruction of the oligodendroglia.
0 Symptoms may progress progressively, resulting in death.
Subacute Combined Degeneration (Neuro-Anemic Syndrome)
It occurs due to vitamin B12 deficiency.
It affects the brain, cerebellum, spinal cord, optic nerve and peripheral nerves.
The first finding is paresthesias in the hands and feet.
CSF is usually normal.
Gait instability, ataxic gait
Weakness in extremities
The posterior cord of the spinal cord is affected.
Decrease in deep sense, vibration and position sense is a constant finding.
Spasticity, DTR changes (increase, decrease)
Clonus, Babinski positivity
Mental findings: Dementia, confusion, depressive psychosis are rare.
Optic neuropathy
Autonomic signs, impotence, sphincter failure
The diagnosis is made by measuring the serum cobalamin level.
Central Pontine Myelinosis
Caused by rapid correction of hyponatremia
Awake deficit, pyramidal quadriparesis and pseudobulbar palsy.