Two pelvic bones (left and right) articulating with the axial skeleton via the sacrum.<br />The pelvic bones are each made up of three bones:<br />Ilium<br />ishium<br />pubis<br />These bones are fused by puberty to form the pelvic bone.<br />The pelvic girdle can only move as a unit (L and R shoulder girdles can move independent of each other<br />
Hip flexors<br />iliopsoas(iliacus, psoas major and minor)<br />pectineus<br />rectus femoris<br />sartorius<br />gracilis<br />tensor fasciae latae<br />rectus femoris<br />Hip extensors<br />gluteus maximus<br />biceps femoris<br />semitendinosus<br />semimembranosus<br />
Proximal limb girdle syndromes<br />Most common pattern of muscle weakness<br />Predominantly the proximal muscles of legs and arms <br />Distal muscles are also involved in much lesser extent.<br />Neck flexors and extensors also frequently involved.<br />Seen in most hereditary and acquired myopathies<br />
MRC scale expanded version<br />5 normal power<br />5- equivocal, barely detectable weakness<br />4+ definite but slight weakness<br />4 able to move against gravity and some resistance<br />4- capable of minimal resistance<br />3+ capable of transient resistance collapse abruptly<br />3 active movement against gravity<br />3- able to move against gravity but not throuh full range<br />2 able to move with gravity eliminated<br />1 trace contraction<br />0 no contraction<br />
Temporal evolution<br />Duchenne muscular dystrophy usually identified by 3yrs of age<br />Most FSHD and LGMD begins in adolescence or later<br />Dermatositis occurs in children and adults<br />Polymyositis rarely occurs in children but in any decade in adult life<br />Inclusion body myositis occurs most commonly in te elderly.<br />Myopaties with acute or sub acute progression- dermatomyositis and polymyositis<br />Chronic slow progression over years- muscular dystrophies<br />Non progressive weakness – congenital myopaties<br />
Pattern recognition approach to proximal limb girdle syndrome<br />
Valley sign<br /><ul><li>In deltoid muscle, only the central fibres originating from the acromion process are enlarged
Inferomedial part of infraspinatus muscle is enlarged</li></li></ul><li>Proximal > distal<br />Lower limbs earlier than upper limbs<br />Varied muscle involvement in various subtypes<br />Limb girdle dystrophies<br />
characteristic wide-based stance is due to striking preservation of hip abductors.<br />
Facioscapulohumeral dystrophy<br />Onset is between 7-27 years<br />Initially face is involved, in particular zygomaticus , orbicularisoculi & orbicularisoris<br />Masseter ,temporalis , extraocular & pharyngeal muscles are spared<br />
Scapular fixators –latissimusdorsi, lower trapezius ,rhomboids & serratus anterior are involved<br />Deltoid is spared<br />Biceps weakness >triceps weakness<br />Forearm muscles are normal<br />POPEYE EFFECT<br />
Polyhill sign<br />six "hills" (1) enlarged infraspinatus muscle (2) superior angle of scapula (3) prominence of acromio-clavicular joint due to wasting of trapezius muscle, (4) prominence of infero-lateral part of the deltoid muscle (5) some preserved bulk in the middle of the wasted biceps brachii (6) prominent brachioradialis muscles<br />
Inflammatory myopaties<br />polymyositis, dermatomyositis - Proximal > distal. Ocular and facial muscles almost never affected. Symmetrical involvement.<br />IBM - Proximal, distal and quadriceps, asymmetrical involvement.<br />
Distribution of weakness<br />Scapuloperoneal- scapuloperonealdystrophy, emery dreifuss dystrophy, LGMD 1B, LGMD-2A, sarcolycanopathies, LGMD-2I, acid maltase deficiency.<br />Facioscapular- FSHD<br />Distal arm proximal leg weakness involving quadriceps – inclusion body myositis. In addition, weakness is assymetrical.<br />Ptosis and facial weakness with out ophthalmoplegia- FSHD and myotonic dystrophy.<br />
In 95% of cases, infants die from complications of the disease by 18 months. </li></li></ul><li>SMA TYPE2<br /><ul><li>An unusual feature of the disease is a postural tremor affecting the fingers. This is thought to be related to fasciculations in the skeletal muscles
Pseudohypertrophy of the gastrocnemius muscle, musculoskeletal deformities, and respiratory failure can occur.
The lifespan of patients with SMA type II varies from 2 years to the third decade of life. Respiratory infections account for most deaths. </li></li></ul><li>SMA type 3<br /><ul><li>SMA type III (Kugelberg-Welander, chronic juvenile, walkers) appear 18 months – adult.
Slowly progressive proximal weakness. Most can stand and walk but have trouble with motor skills, such as going up and down stairs.
Bulbar dysfunction occurs late in the disease.
Patients may show evidence of pseudohypertrophy.
The disease progresses slowly, and the overall course is mild. Many patients have normal life expectancies. </li></li></ul><li>SMA Type 4<br /><ul><li>Adult onset, age of onset after 20yrs, mean age after 30 yrs and autosomal recessive.
Characteristic presentation is of a slowly progressive limb girdle weakness and is otherwise called pseudomyopatic SMA.
Fasciculations are seen in 75% patients, quadriceps weakness is often prominent.
Bulbar weakness, bony deformities, respiratory weakness rare.</li></li></ul><li>Creatinekinase<br />Single most useful lab investigation<br />Degree of ck elevation is helpful.<br />In Duchene dystrophy invariably associated with increase in CK at least 10 times (often up to 100 times).<br />Most other myopaties have lesser elevations except cavelinopaty(1C), calpainopaty(2A), dysferlinopaty(2B).<br />Inflammatory myopaties- polymyositis and dermatomyositis than inclusion body myositis.<br />CK levels not elevated or lowered – profound muscle wasting, corticosteroid administration, collagen disease, alcoholism, or hyperthyroidism.<br />
Muscle biopsy<br />Tissue can be obtained by either open or closed procedure<br />Muscles that are severely weak (MRC grade 3 or less) should not be biopsied.<br />Muscles recently studied by needle EMG should be avoided; artifacts created by needle insertion.<br />Biopsy should be taken from muscles having grade 4 strength <br />Muscle of choice- upper limb –deltoid, lower limb- vastuslateralis.<br />
Muscle biopsy specimen are studied trough histological, immunocytochemical, biochemical, electronmicroscopic, genetic techniques.<br />Typical myopathic appearance- central nuclei, both small and hypertrophic round fibers, split fibers, degenerating regenerating fibers<br /><ul><li>polymyositis - mononulearinflamatory cells composed of cytotoxic T cells(CD8>CD4) and macrophages nonnecrotic muscles in endomysium
In dermatomyositis - perifascicular atrophy & expression of immune attack complex
In inclusion body- endomyseal inflammation and invasion of non necrotic muscle fibers similar to polymyositis, fibers show rimmed vacuoles and abnormal amyloid deposition</li></li></ul><li>Molecular genetics <br />Duchenne muscular dystrophy<br />Fascioscapulohumeral muscular dystrophy<br />LGMD 1B, 1C, 2A, 2B, 2C-F, and 2I<br />