Features
Features:

Product Tour >

Edraw AI >

Paid Plans:

Individuals >

Business >

Eduaction >
Resources
Blog

History

How-tos & Tips

Discovery

Biography

Business Analysis

Examples

AI concept Map

Free AI Mind Map Generator

Onenote Mind Map

Bcg Matrix Examples

Nike Marketing Strategy

Unilever SWOT Analysis

Make Mind Maps in Google Docs

Guide

FAQs

What's New

Resource Center
Templates
All Templates

Brain Storming Templates

Strategy and Planning Templates

Project Management Templates

Product Management Templates

Human Resources Templates

Agile Workflow Templates

Marketing Templates

Education Templates

Fun and Games Templates

User Gallery
Download
Pricing
Enterprise

MindMap Gallery Neurology Chapter 3 Demyelinating Diseases

Neurology Chapter 3 Demyelinating Diseases

Neurology Chapter 3 Demyelinating Diseases Mind Map, Demyelinating diseases are a group of diseases characterized by the destruction/loss of myelin in the brain and spinal cord.

Edited at 2024-03-25 23:39:03

PlotWizard

Recent works View more works>>

Neurology Chapter 3 Demyelinating Diseases

PlotWizard

Recent works View more works>>

Recommended to you
Outline

Neurology Chapter 3 Demyelinating Diseases

Section 1 Overview

【Anatomy and Physiology】

1. Myelin is a lipid cell membrane wrapped around the axons of myelinated nerve fibers and is composed of the cell membranes of myelin-forming cells.

2. The myelin-forming cells of the central nervous system are oligodendrocytes, while the peripheral nervous system is Schwann cells; one cell of the former can provide internodal myelin sheath for more than 40 adjacent axons, and its constituent proteins are mainly proteolipoproteins. (PLP), myelin basic protein (MBP) and myelin-associated glycoprotein (MAG); the latter only provides internodal myelin for one axon per cell, and its constituent proteins are mainly P0, P1, and P2 proteins.

3. Physiological functions of myelin: ① Conducive to the rapid conduction of nerve impulses; ② Insulating effect on nerve axons; ③ Protective effect on nerve axons

[Definition] It is a group of diseases mainly characterized by destruction/loss of myelin in the brain and spinal cord.

【Classification】

hereditary

Disorders of neural myelin metabolism (leukodystrophy) due to genetic factors leading to deficiency of certain enzymes

Acquisition

Demyelinating diseases secondary to other diseases: ischemic-hypoxic diseases (such as delayed leukoencephalopathy after CO poisoning), nutritional deficiency diseases (such as subacute combined degeneration), central pontine myelinolysis, viruses Diseases caused by infections (such as SSPE, progressive multifocal leukoencephalopathy)

Primary immune-mediated inflammatory demyelinating diseases - Idiopathic inflammatory demyelinating diseases of the central nervous system (IIDD): multiple sclerosis (MS), neuromyelitis optica (NMO), concentric sclerosis ( Balo's disease), disseminated encephalomyelitis (DEM), clinically isolated syndrome (CIS), neoplastic inflammatory demyelinating disease (TIDD)

[Pathology] Three recognized pathological standards: ① Destruction of the myelin sheath of nerve fibers, mainly located in the white matter, showing multiple small disseminated lesions, which can also merge into larger lesions; ② Sleeve-like infiltration of inflammatory cells around the small veins ; ③ Nerve cells, axons and supporting tissues remain relatively intact, without Wallerian degeneration/secondary conduction tract degeneration

Section 2 Multiple sclerosis (MS)

[Definition] It is an immune disease mainly characterized by chronic inflammatory demyelinating lesions of the central nervous system, manifesting as focal symptoms and signs of the optic nerve, spinal cord and brain, chronic disease course, and repeated attacks; it is the most common central nervous system disease. Primary demyelinating diseases of the nervous system

[Cause] Autoimmune factors (immune attack against myelin basic protein (MBP), mainly mediated by T cells), genetic factors, environmental factors (infection, vitamin D and sunlight, smoking)

[Pathogenesis] ①Viral infection theory: such as HBV, HHV-6; ②Autoimmune theory: Experimental allergic encephalomyelitis (EAE)

[Pathology] The recurrence stage mainly manifests as inflammatory demyelination, and the progressive stage mainly manifests as neurodegeneration; the lesions can involve the cerebral white matter, spinal cord, brainstem, cerebellum and optic nerve; demyelinating lesions are most common in the anterior horn of the lateral ventricle.

[Clinical manifestations] More common in women between 20 and 40 years old; often subacute onset

Features

Multiple in space (DIS): refers to multiple lesions in different locations; common first symptoms: ① Optic neuritis; ② Acute myelitis; ③ Cerebellar ataxia; ④ Various symptoms of brainstem damage

Diversity in time (DIT): refers to the course of remission-relapse

The main symptoms

Eyes: Unilateral acute optic neuritis/retrobulbar optic neuritis, vision loss, and may include ophthalmoplegia, diplopia, nystagmus, and internuclear ophthalmoplegia

Limb weakness (most common): generally more obvious in the lower limbs, with asymmetrical paralysis the most common; hyperreflexia of tendons (can also be normal in the early stage), disappearance of shallow reflexes, and positive pathological reflexes

Paresthesia: numbness of limbs/trunk/face, ant-like sensation, itching, burning pain, deep sensory disturbance

Cerebellar symptoms: nystagmus, dysarthria, ataxia, intention tremor

Fatigue: exercise intolerance or resting fatigue

Episodic symptoms: short-lasting sensory/motor disturbances that can be triggered by specific factors (such as hyperventilation)

Manifestations: tonic spasms, paresthesia, dysarthria, ataxia, epilepsy, pain and discomfort, general unconsciousness and EEG abnormalities

Lhermitte's sign: It manifests as a tingling/lightning-like sensation that can be induced when passively flexing the neck, radiating from the neck along the spine to the thighs/feet; it is due to the local traction force on the spinal cord when flexing the neck/ Pressure ↑, caused by irritation of the posterior cord of the demyelinated cervical spinal cord

Psychiatric symptoms: more common; manifested as depression, irritability, bad temper, euphoria, apathy, etc.

Types

Relapsing-remitting MS (RR-MS): The most common; characterized by acute exacerbation of neurological symptoms with complete/incomplete remission. Secondary Progressive MS (SP-MS): Relapsing-remitting MS, disability continues to progress 10 years after onset, With/without recurrence, incomplete remission

Primary progressive type (PP-MS): more common in men over 30 years old; disability continues to progress at onset and lasts for at least 1 year without recurrence; symptoms are more common in spinal cord/cerebellar symptoms

Progressive-relapsing (PR-MS): Acute disease onset based on the primary progressive disease course

【Auxiliary inspection】

cerebrospinal fluid

Significance: Provide a basis for the clinical diagnosis of primary progressive type and the differential diagnosis of MS

Performance during acute attack: mild to moderate cell count (<50×106/L), mainly lymphocytes (T cells); mild protein (but <1.0g/L), mainly globulin; IgG Intrathecal synthesis ↑ (CSF-IgG index ↑/multiple >0.7, CSF-IgG oligoclonal band (OB) positive but serum absent)

evoked potential

Abnormalities (especially visual evoked potentials) → helpful in detecting subclinical cases

MRI

May help identify asymptomatic lesions; MS with normal MRI is rare

It manifests as multiple round T1 hypointense and T2 hyperintense lesions of different sizes; characteristics: ① located in the white matter, around the ventricles, and at the junction of gray and white matter; ② the lesions are arranged vertically in a comb-like manner with the ventricles (Dawson's finger sign). The corpus callosum lesions can be "black holes" with ring enhancement in T1 in the acute phase; ③ one lesion must be subcortical and one lesion under the tentorium; ④ the spinal cord may have demyelinating lesions, but the length should not exceed 3 vertebral segments. The spinal cord lesion is equivalent to one intracranial lesion; ⑤The total number of new and old lesions is not less than 9

【diagnosis】

1. Internuclear ophthalmoplegia, Uhthoff phenomenon (decreased vision after increased body temperature), and Lehrmi's syndrome are the three more characteristic symptoms of this disease.

2. Pay attention to clinically isolated syndrome (CIS): refers to an acute/subacute single demyelinating lesion in the central nervous system when other diseases are excluded, with symptoms lasting for more than 24 hours; about 70% will later convert to MS. /NMO, about 15% are stable without deterioration and progression, and 5% turn into non-demyelinating diseases.

【treat】

acute attack period

Purpose: Reduce symptoms and reduce disability as soon as possible

First choice: high-dose methylprednisolone pulse therapy; it can accelerate the recovery of acute relapse and shorten the course of relapse, but it cannot improve the degree of recovery, and long-term use cannot prevent relapse.

Others: plasma exchange, IVIg

relapsing-remitting

Disease-modifying therapy (DMT): Reduce relapse, reduce the number of brain/spinal cord lesions, delay the accumulation of disability, and improve the quality of life; such as beta-interferon (reduce relapse and disability rates), glatiramer acetate (GA), natalizumab monoclonal antibody, fingolimod, teriflunomide

progress period

Cyclophosphamide, Mitoxantrone

Symptomatic treatment

Fatigue: adequate rest, amantadine/modafinil

Difficulty walking: Dalfampridine (central potassium antagonist)

Bladder dysfunction: Carbamylcholine chloride may be useful for urinary retention, and propantheline bromide may be used for urinary incontinence.

Pain: Baclofen, carbamazepine, or clonazepam may be helpful

Cognitive impairment: Donepezil and rehabilitation training can be used

Depression: Psychotherapy, SSRI

patient education

[Prognosis] Factors with better prognosis: young age, benign type, acute onset, single symptom

Section 3 Other demyelinating diseases of the central nervous system

1. Neuromyelitis optica (NMO)/Devic disease

[Definition] It is an immune-mediated acute/subacute demyelinating disease that causes simultaneous/sequential involvement of the optic nerve and spinal cord.

[Clinical manifestations] More common in women; acute/subacute onset, unilateral/bilateral optic neuritis and acute myelitis are the main manifestations of this disease; some may be accompanied by other autoimmune diseases

【Differential Diagnosis】

2. Acute disseminated encephalomyelitis (ADEM)

[Characteristics] It is an acute demyelinating disease that occurs after infection (especially rash infection, especially measles infection) or vaccination (especially rabies vaccine); it mainly affects the brain and spinal cord, with an incubation period of 1 to 2 weeks.