Medical Research Council (MRC) Scale for Muscle Strength

The patient's effort is graded on a scale of 0-5:
Grade 5: Muscle contracts normally against full resistance.
Grade 4: Muscle strength is reduced but muscle contraction can still move joint against resistance.
Grade 3: Muscle strength is further reduced such that the joint can be moved only against gravity with the examiner's resistance completely removed. As an example, the elbow can be moved from full extension to full flexion starting with the arm hanging down at the side.
Grade 2: Muscle can move only if the resistance of gravity is removed. As an example, the elbow can be fully flexed only if the arm is maintained in a horizontal plane.
Grade 1: Only a trace or flicker of movement is seen or felt in the muscle or fasciculations are observed in the muscle.
Grade 0: No movement is observed.



Clinical grading scale employed for functional assessments
Grade 0: normal.
Grade 1: no disability; minor sensory signs or areflexia.
Grade 2: mild disability; ambulatory for >200 m; mild weakness in one or more limbs and sensory impairment.
Grade 3: moderate disability; ambulatory for >50 m without stick; moderate weakness MRC Grade 4 and sensory impairment.
Grade 4: severe disability; able to walk >10 m with support of stick; motor weakness MRC Grade 4 and sensory impairment.
Grade 5: requires support to walk 5 m; marked motor and sensory signs.
Grade 6: cannot walk 5 m, able to stand unsupported and able to transfer to wheelchair, able to feed independently.
Grade 7: bedridden, severe quadriparesis; maximum strength MRC grade 3.
Grade 8: respirator and/or severe quadriparesis; maximum strength MRC grade 2.
Grade 9: respirator and quadriplegia.
Grade 10: dead.




Reference:
Medical Research Council. Aids to the examination of the peripheral nervous system, Memorandum no. 45, Her Majesty's Stationery Office, London, 1981.
Hahn AF, Bolton CF, Pillay N, et al. Plasma exchange therapy in chronic inflammatory
demyelinating polyneuropathy. A double-blind, sham controlled, cross-over study.
Brain 1996;119:1055–66. [Medline]
Paternostro-Sluga T, Grim-Stieger M, Posch M, Schuhfried O, Vacariu G, Mittermaier C, Bittner C, Fialka-Moser V. Reliability and validity of the Medical Research Council (MRC) scale and a modified scale for testing muscle strength in patients with radial palsy. J Rehabil Med. 2008 Aug;40(8):665-71.

Conducting a Neurological Examination in English

Medical Education de UCD School of Medicine and Medical Science

Bilateral Internuclear Ophthalmoplegia in Multiple Sclerosis

A 45-year-old man with multiple sclerosis presented with worsening weakness in his right leg and double vision. Neurologic examination revealed horizontal diplopia during lateral gaze in both eyes. The patient had an adduction deficit in the right eye and nystagmus in the left eye on leftward gaze (Panel A). He also had an adduction deficit in the left eye and nystagmus in the right eye on rightward gaze (Panel B). Upward gaze (Panel C), downward gaze (Panel D), and normal primary position (Panel E) were unremarkable. Internuclear ophthalmoplegia is characterized by impaired horizontal eye movement that is caused by a lesion in the medial longitudinal fasciculus, a fiber tract that rises from the abducens nucleus in the pons to the contralateral oculomotor nucleus in the midbrain. Lesions in the medial longitudinal fasciculus result in the failure of adduction on attempted lateral gaze. Any brain-stem syndrome can interrupt the medial longitudinal fasciculus and result in impaired horizontal eye movement, but the most frequent underlying cause is multiple sclerosis. This patient had internuclear ophthalmoplegia in both eyes due to demyelinating lesions. Glucocorticoids were administered intravenously, but the deficits did not resolve. On follow-up at 2 months, the patient's gait had improved, but the internuclear ophthalmoplegia remained.

Weber and Rinnè tests

Learn how to assess hearing problems with simple tests 

Chvostek's and Trousseau's Signs

A 38-year-old man presented to the emergency department with facial paresthesias and upper-extremity muscle cramping. His symptoms were progressive, beginning as mild paresthesias on postoperative day 1 by the time he presented, they had been getting worse for about 24 hours. His medical history was noteworthy only for papillary thyroid carcinoma, for which he had undergone a total thyroidectomy 2 days earlier. Physical examination revealed apparent Chvostek's sign (Figure 1A and Video 1) and Trousseau's sign (Figure 1B and Video 2), a result of postsurgical acquired hypoparathyroidism. His total calcium level was 5.8 mg per deciliter (normal range, 8.4 to 10.3) (1.45 mmol per liter [2.1 to 2.6]), his free calcium level was 1.68 mEq per liter (normal range, 2.24 to 2.64) (0.84 mmol per liter [1.12 to 1.32]), and his serum phosphate level was 6.6 mg per deciliter (normal range, 2.7 to 4.5) (2.13 mmol per liter [0.87 to 1.45]). The parathyroid hormone level was 7 pg per milliliter (normal range, 15 to 65).

Gradenigo syndrome

A 28-year-old woman presented with fever, double vision, and facial pain. Neurologic examination showed neck stiffness, pain in the distribution of the right trigeminal nerve, and right abducens palsy (figure 1). Tympanic membranes were normal. MRI revealed sphenoid sinusitis, basilar pachymeningitis, and clivus osteomyelitis (figure 2). CSF analysis showed pleocytosis, increased protein contents, decreased glucose levels, and positive cultures for Staphylococcus aureus. The triad of suppurative otitis media, pain in the distribution of the trigeminal nerve, and abducens palsy is called Gradenigo syndrome.¹ While it most often affects children, it may occur in adults and may rarely present without otitis media.² While bone compromise is usually confined to the petrous apex, it may extend to sphenoid sinuses, clivus, and basal meninges.

Figure 1

Photograph of the patient shows isolated right abducens palsy

Figure 2 Head MRI

Contrast-enhanced T1-weighted MRI of the head shows mucosal thickening of sphenoid sinuses (arrowheads), basilar and right middle fossa pachymeningitis (small arrows), and osteomyelitis of the clivus (large arrow). While the right abducens nerve is not well visualized, it could be inferred in the axial sections (upper row) that it is entrapped throughout the Dorello channel and the cavernous sinus.