GENERALIZED WEAKNESS
Generalized Weakness:Case 35-2012 (Severe Hypothyroidism)
MUSCLE WEAKNESS: - True or Objective Muscle Weakness (Y/N)
- Localization: If Y, Generalized or Localized - If Localized, Symmetrical or Asymmetrical - If Symmetrical, Proximal or Distal or specific pattern present or not (Examination should evaluate for atrophy, fasciculations, tone, distribution, reflexes, babinski sign)
- Etiology: Based on each type- DDx:
Approach to the adult patient with the complaint of weakness (Algorithm) Up-To-Date
Differential diagnosis of weakness Up-To-Date Major causes of myopathy Up-To-Date Case 29-2005: A 68-Year-Old Man with Periorbital Swelling, Rash, and Weakness Respiratory muscle weakness due to neuromuscular disease: manifestations and evaluation Up-To-Date Causes of neuromuscular disease Up-To-Date
Case 3-2015: A 60-Year-Old Woman with Abdominal Pain, Dyspnea, and Diplopia (Botulism)
Signs that Distinguish the Origin of Weakness Harrisson's PIM www.orthobullets.com (Nerve and Muscle Palsy) Hopkins peripheral Nerve Surgery Center
Tests for Cervical-Thoracic Nerves
Sensory Distribution of Upper Limb
Motor Examination of Upper Limb - Extension of the arms at elbow (Triceps; C6, C7, C8; Radian N)
- Flexion of the arms at elbo÷w with forearm midway between pronation and supination (Brachioradialis: C5,C6; Radial N)
- Patient pronates the forearm against resistance (Pronator Teres; C6, C7; Median N)
- Extending the thumb at the MCP joint against resistence (Extensor Pollicis Brevis; C7, C8; Posterior Interosseous N)
- Flexion of the distal phalanx of the index finger against resistance with the middle phalanx fixed (C7, C8 Flexor Digitorum Profundus I and II; Median N)
- Same as 5 but of little finger (C7, C8; Flexor Digitorum Profundus III and IV; Ulnar N)
- Same as 5 but of Thumb (Flexor Pollicis Longus; C7, C8; Anterior Interosseous N)
- Abduction of the Thumb at right angle to the palm against resistance (Abductor Pollicis Brevis; C8, C1; Median N)
- Touch the base of the little finger with the thumb against resistance (Opponens Pollicis; C8, T1; Median N)
- Abduction of the little finger against resistance (Abductor Digiti Minimi; C8, T1; Ulnar N)
- Extensor Carpi Radialis Longus (Radial N)
- Brachioradialis (Radial N)
- Supinator (Radial N)
- Pronator Teres (Median N)
- Flexor Carpi Radialis (Median N)
- Extensor Carpi Ulnaris (Posterior Interosseous N)
- Extensor Digitorium (Posterior Interosseous N)
- Abductor Pollicis Longus (Posterior Interosseous N)
- Extensor Pollicis Brevis (Posterior Interosseous N)
- Flexor Digitorum Profundus I and II (Median N)
- Flexor Pollicis Longus (Anterior Interosseous N)
- Flexor Digitorum Profundus III and IV (Ulnar N)
- Flexor Digitorium Superficialis (Median N)
- Flexor Carpi Ulnaris (Ulnar N)
- Abductor Pollicis Brevis (Median N)
- Opponens Pollicis (Median N)
- 1st Lumrical-Interosseous Musces (Median and Ulner N)
- Abductor Digiti Minimi (Ulnar N)
- Flexor Digiti Minimi (Ulnar N)
- First Dorsal Interosseous Muscles (Ulnar N)
- Second Palmar Interosseous Muscle (Ulnar N)
- Adductor Pollicis (Ulnar N)
Sensory Distribution of Upper Limb
Motor Examination of Upper Limb - Extension of the arms at elbow (Triceps; C6, C7, C8; Radian N)
- Flexion of the arms at elbo÷w with forearm midway between pronation and supination (Brachioradialis: C5,C6; Radial N)
- Patient pronates the forearm against resistance (Pronator Teres; C6, C7; Median N)
- Extending the thumb at the MCP joint against resistence (Extensor Pollicis Brevis; C7, C8; Posterior Interosseous N)
- Flexion of the distal phalanx of the index finger against resistance with the middle phalanx fixed (C7, C8 Flexor Digitorum Profundus I and II; Median N)
- Same as 5 but of little finger (C7, C8; Flexor Digitorum Profundus III and IV; Ulnar N)
- Same as 5 but of Thumb (Flexor Pollicis Longus; C7, C8; Anterior Interosseous N)
- Abduction of the Thumb at right angle to the palm against resistance (Abductor Pollicis Brevis; C8, C1; Median N)
- Touch the base of the little finger with the thumb against resistance (Opponens Pollicis; C8, T1; Median N)
- Abduction of the little finger against resistance (Abductor Digiti Minimi; C8, T1; Ulnar N)
Tests for Lumbo-Sacral Nerves - Tibialis anterior (L5)
- Extensor digitorum longus (L5)
- Extensor hallucis longus (L5)
- Popliteus (L5)
- Tibialis posterior (L5)
- Peroneus longus (S1)
- Peroneus brevis (S1)
- Gastrocnemius (S1)
- Soleus (S1)
- Plantaris (S1)
- Flexor digitorum longus (S2)
Tests for Peripheral Nerves
Clinical Question
55 yo M is seen in the clinic for Left hand weakness. Where is the lesion?
Proximal muscle strength of biceps and triceps is good. Wrist flexion and extension is good. Flexion of the distal phalanx when holding the middle phalynx is good. Extension of all the fingers are not good. Thumb Decreased opposition. Extension is week. Cannot Abduct or adduct Interossei
What are the extensor muscles of the distal phalanx? What are the extensor muscles at the wrist
- Posterior interosseous Never Injury
- Very much possible; mostly motor nerve with no or limited sensory innervation
- Does affect the common extensors and deep extensors of hand
- Weakness in finger, wrist and thumb extension is common
- First metacarpal extension weakness is common
- INABILITY to extend in Neutral or Ulnar deviation; but INTACT wrist extenion is radial deviation due to intact ERCL (radial N) and absent ECU (PIN)
- Has no cutaneous innervation
- Cannot explain inability to abduct or adduct interossei which are supplied by deep ulnar nerve
- Reference: http://www.orthobullets.com/hand/6023/posterior-interosseous-nerve-compression-syndrome
- Radial Nerve Injury before the branch of the PIN
- Less likely
- Radial Nerve divide into PIN and Superficial Radial Nerve at the level of elbow
- Hence, any injury proximal to the division should have sensory deficit at the dorsal aspect of thumb, index(up to PIP), and middle finger (lateral aspect, up to PIP)
- References
- Radial Nerve (Orthobullet.com)
- Superficial Radial nerve (orthobullet.com)
- Ulnar nerve injury
- Very much possible
- Injury to deep ulner nerve can explain the following
- Lumbrical Muscle : Extend PIP and DID:
- 1st and 2nd Lumbrical is innervated by Median N. Hence, 1st and 2ndn Lumbricals should be spared
- 3rd and 4 th Lumbrical is innervated by Ulner N (little finger and index finger)
- Palmar interossei: Adduct. Deep Ulner N
- Dorsal Interossei: Abduct. Deep Ulner N
- This offers the best explanation of the patient finding.
|
