myopathy for medical students

MYOPATHYMYOPATHY

Prof. Ashraf AbdouProf. Ashraf Abdou

Neuropsychiatry deptNeuropsychiatry dept

Faculty of medicineFaculty of medicine

Alexandria univAlexandria univ

Etiological Classification of Etiological Classification of MyopathiesMyopathies

HEREDITARYHEREDITARY Muscular Muscular

DystrophiesDystrophies– Duchenne’s Duchenne’s

MyotoniasMyotonias

ACQUIREDACQUIRED InflammatoryInflammatory EndocrineEndocrine Drug-induced Drug-induced

and toxic and toxic myopathiesmyopathies– EtOH, steroids, EtOH, steroids,

statinsstatins

When you think about When you think about muscle disease?muscle disease?

Weakness:Weakness:– Child: delayed sitting, standing, walkingChild: delayed sitting, standing, walking

– Adult: Adult: going upstairs – walking long distance – walking going upstairs – walking long distance – walking

– standing– standing

Difficulty in carrying heavy objects – difficulty in Difficulty in carrying heavy objects – difficulty in combing haircombing hair

No sensory complaintNo sensory complaint

No sphincters control problemNo sphincters control problem

MayalgiaMayalgia

When you think about When you think about muscle disease?muscle disease?

Clincal examinationClincal examination

– Weakness: Bilateral – Weakness: Bilateral – symmetrical – proximalsymmetrical – proximal

– Muscle atrophyMuscle atrophy

When you think about When you think about muscle disease?muscle disease?

Clincal examinationClincal examination

– No sensory abnormalitiesNo sensory abnormalities

– Skeletal deformitiesSkeletal deformities

INVESTIGATIONSINVESTIGATIONS

InvestigationsInvestigations

Muscle enzymesMuscle enzymes

– Creatinine kinase [CK]Creatinine kinase [CK]

– AldolaseAldolase

ElectromyogramElectromyogram

InvestigationsInvestigations

Muscle biopsy for Muscle biopsy for pathological studypathological study

Muscular DystrophyMuscular Dystrophy

Group of inherited diseases Leads to chronic

progressive muscle atrophy Usually appears in early

childhood Most types result in total

disability and early death

Duchenne’s muscle Duchenne’s muscle dystrophydystrophy

Prevalence of DMDPrevalence of DMD

Affects 1 in Affects 1 in 3500 newborn 3500 newborn malesmales

1/3 of these 1/3 of these with previous with previous family historyfamily history

2/3 sporadic2/3 sporadic

DYSTROPHIN GENEDYSTROPHIN GENE

NORMAL

DUCHENNE

BEKER’s

Muscles that are affectedMuscles that are affected

In the early stages, In the early stages, Duchenne MD Duchenne MD affect the pectoral affect the pectoral muscles , the muscles , the trunk, hamsterings, trunk, hamsterings, calf musclecalf muscle

These weaknesses These weaknesses lead to difficulty in lead to difficulty in rising, climbing rising, climbing stairs and stairs and maintaining maintaining balance.balance.

Symptoms of DMDSymptoms of DMD

Delayed developmental Delayed developmental

milestonesmilestones

Loss of motor skillsLoss of motor skills

Characteristic gaitCharacteristic gait

Calf hypertrophyCalf hypertrophy

Clumsiness/frequent fallsClumsiness/frequent falls

PSEUDOHYPERTROPHY

ATROPHY

Difficulty rising Difficulty rising (Gower’s sign)(Gower’s sign)

PrognosisPrognosis

Prenatal diagnosisPrenatal diagnosis

This is achieved by studying the This is achieved by studying the

foetus’s own DNA on a chorion villus foetus’s own DNA on a chorion villus

biopsy.biopsy.

The test is performed on a tiny piece The test is performed on a tiny piece

of the developing placenta usually at of the developing placenta usually at

the 11the 11thth –12 –12th th week of pregnancy.week of pregnancy.

Treatment optionsTreatment options

FutureFuture