Sistem Neuromuskular

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Sistem Neuromuskular
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Sistem Neuromuskular

• Tiga komponen utama Neuromuskular
• Nerve
• Neuromuscular junction
• Muscle

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Upper Motor Neuron

• Semua neuron yang menyalurkan impuls motorik
  secara langsung ke LMN atau melalui
  interneuronnya, tergolong dalam kelompok UMN.
  Neuron-neuron tersebut banyak terdapat di girus
  presentralis dinamakan juga korteks motorik.
  Melalui aksonnya neuron korteks motorik
  menghubungi motoneuron di kornu anterior medulla
  spinalis.

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Area Motorik
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Upper motorneuron
Lower motorneuron
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Lower Motor Neuron

• Merupakan neuron-neuron yang menyelurkan impuls
  motorik pada bagian perjalanan terakhir (kornu
  anterior medula spinalis) ke sel-sel otot
  skeletal.

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Motor end Plate

• Pada ujungnya setiap akson akan bercabang-cabang
  dan setiap cabang menghubungi membrane serabut
  otot. Serabut-serabut otot setiap unit motorik
  berkisar antara 10-500 serabut otot. Tiap serabut
  otot memilki satu motor end plate.

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• Ujung-ujung terminal dari akson mengandung
  mitokondria dan ezim cholin acertyltransferase,
  yang diperlukan untuk sintesis
  neurotransmitter yang dinamakan
  acetylcholine.

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Pelepasan Acetilkolin

• Nerves releasing Achetylcholine at the
  neuromuscular junction (end plate) cause the
  contraction of skeletal muscle. The functional
  unit of a muscle organ is the muscle fiber
  (muscle cell).

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• The muscle fiber contracts in an "all-or-none"
  fashion when stimulated by an action potential.
  The action potential first causes intracellular
  Ca release from the sarcoplasmic reticulum and
  the Ca activates a cascade of events which
  results in the movement of actin over myosin
  (sliding filament theory).

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• Tanda-tanda kelumpuhan UMN
• Hiperrefleksia
• Terdapat refleks patologis
• Tonus otot meninggi atau hipertonia
• Terdapat Klonus
• Tidak terdapat atrofi otot yang lumpuh
• Refleks automatisme spinal (-)

• Tanda-tanda kelumpuhan LMN
• Arefleksia (hilangnya refleks tendo)
• Tidak ada refleks patologis
• Hilangnya tonus otot (flacid)
• Tidak terdapat klonus
• Terdapat atrofi pada otot yang lumpuh

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Gangguan yang menyebabkan kelemahan gerak
(paralysis)

• Kelainan pada otot
• Periodik Paralysis
• Inflamatory miopathy
• Miopati karena steroid
• Rabdomyolisis
• Neuromuscular junction
• Miastenia Gravis
• Botulism
• Tick paralysis
• Lambert Eaton Myastenic Syndrome

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Gangguan yang menyebabkan kelemahan gerak
(paralysis)

• Neuropati akut
• Paraneoplastik
• Vaskulitis (lupus, poliarteritis)
• Neuropati motorik multifokal
• Poliradikulopati akut
• Guillain-Barre syndrome
• Lime Disease
• Sindrome Cauda Equina
• Penyakit Motor neuron
• Poliomyelitis
• Amyotropic Lateral Sclerosis (ALS)

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Gangguan yang menyebabkan kelemahan gerak
(paralysis)

• Medula Spinalis
• Inflamasi (mielitis transversus)
• Mielopati (spondilosis, hematom, infark)
• Otak (Cerebrum, cerebellum)
• Lesi di Pons
• Lesi fokal/multifokal (infark, hematom)

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Jenis Gangguan Saraf

• Polyneuropathy motor, sensory,
• sensorimotor
• Radiculopathy
• Polyradiculopathy
• Plexopathy
• Mononeuropathy isolated
• multiplex

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Klasifikasi kausa

• Toxic
• Drugs, alcohol, organophosphates
• Inflammatory/Immune
• GBS, CIDP
• Vasculitis
• Infective
• Leprosy, Lyme, HIV, Diphtheria
• Traumatic

• Inherited
• HMSN and HLPP
• Amyloid
• Metabolic
• Diabetes
• Vitamins B12, B1, E
• Dialysis, Liver failure
• Paraneoplastic
• sensory (anti-Hu)

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Klasifikasi tipe kerusakan

• Demyelinating
• Axonal
• Small fibre
• Large fibre
• Autonomic

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Physical findings
Nerve NMJ Muscle Reflexes Usually decr. NL or
decr. NL or decr. Atrophy Can be
severe Minimal Variable Fascic. Sometimes None Non
e Sensory loss Sometimes None None
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The Motor Unit
Myopathies
Motor Neurone Disorders
Myasthenia etc
Peripheral Neuropathy
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Gangguan pada saraf

• Variasi
• Cell body, axon myelin
• Fiber size large, small
• Motor, sensory, autonomic
• Distribution focal, multifocal, generalized
• Course acute, subacute, chronic, lifelong
• Etiology genetic, toxic, metabolic, autoimmune,
  traumatic, vascular, infectious

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Gangguan pada Saraf berdasarkan Lokasi

• Radix radiculopathy
• Plexus plexopathy
• Single nerve mononeuropathy
• Several nerves multiple mononeuropathy, mononeuri
  tis multiplex
• All nerves, polyneuropathylength-dependent
• All nerves, polyradiculoneuropathynot
  length-dependent

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Radix

• Segmental loss of
• motor
• atrophy
• weakness
• reflexes
• sensation
• Signs usually minimal symptoms can be severe
  (pain)
• Usually only one limb.

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Plexus

• Pain
• Weakness, atrophy, variable, but usually more
  severe than radiculopathy
• Usually restricted to one limb
• Etiology
• Brachial trauma, neoplasm, idiopathic
• Lumbosacral diabetes, neoplasm

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Single nerve (mononeuropathy)

• Restricted distribution
• Pain, numbness or tingling, atrophy, weakness
• Etiology
• entrapment
• trauma

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Carpal tunnel syndrome

• N.Medianus
• Pain in hand, forearm, arm
• Numbness in median distribution
• Symptoms aggravated by wrist flexion

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Ulnar neuropathy

• Numbness
• Atrophy of first dorsal interosseous
• Weakness
• Compression at elbow
• Entrapment in cubital tunnel
• Distal injury

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Radial nerve Saturday night palsy

• Weakness of wrist finger extensors,
  brachioradialis
• Pressure palsy
• Trauma (humerus fracture)

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Peroneal palsy

• Crossing legs
• Weight loss
• Hospitalization
• Surgery

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Several nerves (mononeuritis multiplex)

• Often painful at onset
• Often sudden
• Deficits in the distribution of several
  peripheral nerves (one at a time)
• Etiology vasculitis

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All nerves Length-dependent (polyneuropathy)

• Lower before upper extremity
• Distal first (feet)
• Atrophy of intrinsic foot muscles
• Decreased ankle jerks
• Stocking, then glove sensory loss
• Distal motor and sensory findings always much
  more severe than proximal

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Polyneuropathy (contd)
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Polyneuropathy (contd)

• Most common kind of neuropathy
• Etiology
• metabolic (diabetes, renal failure)
• nutritional (thiamine, B12 deficiency)
• toxic (heavy metals, organic solvents, some
  drugs)
• familial (Charcot-Marie-Tooth)

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All nerves, not length-dependent(polyradiculoneur
opathy)

• Both proximal and distal weakness
• Variable sensory symptoms
• Autonomic symptoms (pulse, blood pressure,
  urination...)
• Can affect respiration, swallowing
• Autoimmune

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Guillain-Barré Syndrome (GBS)
Merupakan penyakit Autoimmun

• Definisi GBS
• Penyakit demyelinasi akut, yang terutama mengenai
  susunan saraf tepi. Penyakit inflamasi pada
  sistim saraf tepi mempunyai karakteristik adanya
  infiltrasi limfosit dan makrofag dengan destruksi
  myelin
• Derajad dan lokasi kerusakan tergantung saraf
  yang bermyelin Motorik

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Guillain-Barre syndrome

• Progresses over days to lt4 weeks
• Typically ascending weakness
• Reflexes lost early
• Motor symptoms predominate, but can affect
  sensation and autonomic function
• Respiratory failure requires support

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Guillain-Barre syndrome (contd)

• Penyebab autoimmun
• Target Antigen biasanya tidak diketahui
• Pada beberapa kasus Target serangan imun
  gangliosida (GM1, GQ1b)
• Faktor presipitasi
• Infeksi virus (HIV, CMV, varicella zoster)
• Infeksi bakteri (campylobacter jenjuni, typhoid,
  paratyphoid)
• Immunisasi
• Sistemik (Hodgkins disease, leukemia,
  hipertiroidisme, sarkoidosis)
• Transplantasi organ, operasi, kehamilan

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Latar belakang GBS

• Epidemiologi GBS
• 1- 4 kasus/100.000
• Paling banyak pada pria
• Meningkat sesuai usia
• Insidennya bervariasi sesuai musim

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Gambaran klinis GBS

• Gangguan Motorik
• paralisis yang progressif, simetris pada
  extremitas bawah dan atas, bersifat asendern
• dimulai dari distal ke proksimal
• Gangguan sensibilitas Stocking, dan glove
  sensory loss (dysesthesia)
• Gangguan otonom
• penyebab kematian

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Clinical Picture of Polyneuropahty (Valenstein,
2000)
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Gambaran klinis GBS

• Atypical presentations
• Miller-Fisher Syndrome
• Areflexia
• Ophthalmoplegia
• Ataxia

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diagnosis GBS

• Riwayat penyakit sebelumnya atau vaksinasi
• Dari pemeriksaan fisik (Physical Exam)
• Laboratoratorium
• Peningkatan kadar protein pada pemeriksaan LCS
  dan rendahnya jumlah sel di LCS (disosiasi
  sitoalbumin)
• Electromyography adanya blok konduksi saraf

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KRITERIA GBS MENURUT GILROY DAN MEYER (1979)

• Paralisis flasid simetris, difus
• Gejala sensoris subyektif
• Penyembuhan sempurna dalam 6 bulan
• Disosiasi citoalbumin
• Tanpa atau sedikit demam saat muncul paralysis
• AL normal atau lymphositosis dengan sedikit atau
  tanpa kenaikan KED.
• Harus memenuhi 5 kriteria dari 6 kriteria

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Pengobatan GBS

• Fase akut
• Supportive care monitoring fungsi vital
  (perawatn ICU)
• Pemberian IV imunoglobulin (ivIg) 400 mg/kg
  selama 5 hari, plasmapheresis 40-50 ml/kg plasma
  exchange diberikan 4 kali seminggu
• Kortikosteroid
• Artificial ventilation (if necessary) ? paralysis
  diafragma
• Setelah fese akut
• Program rehabilitasi, bladder training, perbaikan
  ADL (activity daily living)

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Summary of nerve disorders

• Root Disk, Herpes zoster
• Plexus Autoimmune, trauma, neoplasm
• Mononeuropathy Trauma, entrapment
• Multiplemononeuropathy Vasculitis...
• Polyneuropathy Toxic, metabolic, nutritional
• Polyradiculo-neuropathy Autoimmune

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Neuromuscular junction
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Disorders of the neuromusuclar junction

• Release of acetyl choline
• Botulism (toxin endopeptidase targeting various
  proteins mediating exocytosis)
• Lambert-Eaton myasthenic syndrome (antibodies to
  voltage-gated calcium channel)
• Acetylcholine receptor blockade
• Myasthenia gravis (antibodies to ACh receptor)

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Myasthenia Gravis

• Kelemahan yang berfluktuasi
• Mata ptosis, diplopia
• Bulbar weakness dysarthria, dysphagia
• Kelemahan otot proksimal
• Kelemahan respirasi
• Normal reflexes
• Normal sensation
• Berkaitan dg thymoma
• Berkaitan dg penyakit autoimun

Penyakit autoimun pada transmisi neuromuskular
junction yang diakibatkan oleh antibodi yang
menyerang reseptor asetilkolin atau melawan
muscle spesific receptor tyrosine kinase
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• Myasthenia gravis is a neuromuscular disease
  leading to fluctuating muscle weakness and
  fatiguability.
• It is an autoimmune disorder, in which weakness
  is caused by circulating antibodies that block
  acetylcholine receptors at the post-synaptic
  neuromuscular junction, inhibiting the
  stimulative effect of the neurotransmitter
  acetylcholine.
• Myasthenia is treated medically with
  cholinesterase inhibitors or immunosuppressants,
  and, in selected cases, thymectomy.
• At 200400 cases per million it is one of the
  less common autoimmune disorders.

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• Muscles become progressively weaker during
  periods of activity and improve after periods of
  rest. Muscles that control eye and eyelid
  movement,
• facial expression, chewing, talking, and
  swallowing are especially susceptible. The
  muscles that control breathing and neck and limb
  movements can also be affected

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Myasthenia Gravis

• Terapi
• Acetyl cholinesterase inhibitors pyridostigmin
  bromida 3x 60 mg
• Plasmapharesis plasma exchange
• Imunoglobulin IV
• Immunosupresan (kontroversi)
• Steroid mulai 12-50 mg
• Azathioprine 50 mg/hari
• Cyclosporine awal 3-4 mg/kg/hari dalam dosis
  terbagi
• Cyclophosphamide dosis 1-2 mg/kg/ hari
• Thymectomy , indikasi
• Timoma
• Generalized myastenia yang tidak terkontrol
  dengan antikolinesterase (lt 50 th, 6-12 bulan
  tidak ada remisi spontan)

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Krisis Mistenia

• Adalah keadaan eksaserbasi penyakit Mistenia
  gravis dimana kelumpuhan menyebabkan episode akut
  kegagalan pernafasan
• Terjadi pada 74 setelah 2 tahun miastenia gravis

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Krisis Mistenia

• Faktor pencetus
• Infeksi, terutama infeksi saluran nafas
• Pemakaian obat2an aminoglikosid, ciprofloksasin,
  klindamisin, propanolol, fenitoin
• Tidak diketahui (30-40)

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Krisis Mistenia

• Terapi
• Kontrol airways, dan perbaiki ventilasi (jika
  perlu menggunakan ventilator)
• Terapi antikolinesterase
• Kortikosteroid
• Plasma axchange atau IV Ig

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Penyakit otot (myopathy)

• Symmetrical proximal weakness
• Reflexes normal (sometimes depressed)
• No sensory loss

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Myopathy (contd)

• Inherited
• Dystrophies
• Congenital myopathies
• Channelopathies
• Acquired
• endocrine
• inflammatory, including autoimmune
• toxic (drugs...)

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Inflammatory myopathies

• Polymyositis
• isolated
• with collagen vascular disease
• Dermatomyositis
• childhood
• adult association with cancer
• others

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Dystrophy Musculorum

• Muscular dystrophy is a genetic condition causing
  muscle weakness

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Dermatomyositis - Polymyositis
KRITERIA DIAGNOSIS Kelemahan otot-otot proksimal
simetris Rash tipikal pada dermatomyositis
Peningkatan enzim otot / plasma muscle enzymes
(CK, aldolase, AST), khususnya creatine
kinase Terdapat korelasi antara beratnya
kelemahan dengan peningkatan enzim Gambaran
myopati pada pemeriksaan needle EMG Gambaran
abnormalitas yang khas pada biopsi otot (nekrosis
serabut otot dan degenerasi, dengan infiltrasi
sel-sel inflamasi)
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Polymyositis

• Polymyositis is a disease of muscle featuring
  inflammation of the muscle fibers
• The cause of the disease is not known
• Polymyositis is slightly more common in females.
  It affects all age groups, although its onset is
  most common in middle childhood and in the 20s
• Weakness of muscles is the most common symptom of
  polymyositis

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Amyotrophic lateral sclerosis

• Lou Gehrig's disease
• Amyotrophic lateral sclerosis (ALS) is a nervous
  system disease that attacks nerve cells called
  neurons in your brain and spinal cord
• The cause of ALS is not known

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Amyotrophic lateral sclerosis

• The disease belongs to a group of disorders known
  as motor neuron diseases, which are characterized
  by the gradual degeneration and death of motor
  neurons.
• In ALS, both the upper motor neurons and the
  lower motor neurons degenerate or die, ceasing to
  send messages to muscles
• At first, this causes mild muscle problems. Some
  people notice
• Trouble walking or running
• Trouble writing
• Speech problems

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Multiple sclerosis

• Multiple sclerosis (MS) is a nervous system
  disease that affects your brain and spinal cord.
  It damages the myelin sheath
• No one knows what causes MS. However, viral and
  autoimmune etiologies have been hypothesized. It
  may be an autoimmune disease
• The symptom can include
• Visual disturbances
• Muscle weakness
• Trouble with coordination and balance
• Sensations such as numbness, prickling, or "pins
  and needles"
• Thinking and memory problems

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Thank you