WCS04 Central Nervous System Flashcards
1
Q
3 key questions in approach
A
- Where is lesion —> Anatomical diagnosis
- brain (hemisphere, brainstem, cerebellum)
- spinal cord, root, plexus
- peripheral nerve
- NMJ (only motor symptom with fasciculation, no sensory deficit)
- muscle (only motor symptom, proximal muscle affected but not distal muscle ∵ proximal much larger bulk) - What is underlying pathology? —> Pathological diagnosis
- Neurological / Functional?
2
Q
History taking
A
- Chief complaint
- Mode of onset
- Duration
- Course
- Associated symptoms
- Risk factors
3
Q
Physical examination
A
- Elicit signs according to history
- General examination (focused)
- conscious state
- body habitus
- dysmorphic features / cutaneous lesions e.g. neurofibromatosis
- posture e.g. hemiplegic posture in stroke
- movement e.g. resting tremor in Parkinsonism
- facial features e.g. ptosis, facial asymmetry, mask facies
- bulbar dysfunction e.g. tube feeding
- respiratory weakness e.g. ventilators
- micturition dysfunction e.g. Foley catheter - Neurological examination (screening vs focused)
- Other systems examinations
- Interpret findings
- normal vs abnormal
- anatomical diagnosis
4
Q
Neurological examination
A
- Higher mental functions
- patient’s ability to provide coherent history
- GCS scale: Eye 4, Verbal 5, Motor 6
- MMSE (30 full mark, ***18/21: Low)
- MoCA (Montreal cognitive assessment) - Speech + Language
- understand?
- able to speak?
- comprehension?
- articulation? - Cranial nerves
- 1, 2: Cerebrum
- 3, 4: Midbrain
- 5, 6, 7, 8: Pons
- 9, 10, 11, 12: Medulla
5
Q
CN1 Olfactory nerve
A
Change in smell
- test with aromatic + non-irritant materials
6
Q
CN2 Optic nerve
A
- Visual acuity
- Snellen’s chart - Pupil
- size, shape, symmetry - Direct + Consensual light reflex
- Accommodation reflex
- Visual field
- Fundus with Ophthalmoscope
- optic disc atrophy
- papilloedema
- macular edema
- retinopathy
7
Q
Ocular movement
A
EOM: SO: Abduct + Depress IO: Abduct + Elevate SR: Adduct + Elevate IR: Adduct + Depress
Test: SO望左*下 IO望左*上 SR望右上 IR望右下
8
Q
Diplopia
A
- Confirm with covering one eye —> see if still diplopia
- Image may be affected: False image
- not lie in centre
- side by side with normal image
- at angle with each other
9
Q
CN5 Trigeminal nerve
A
- Muscles of mastication
- Sensory
- ophthalmic CNV1
- maxillary CNV2
- submandibular CNV3 - Jaw jerk reflex
- brisk: UMN lesion i.e. above pons - Corneal reflex
- afferent: **CNV1
- efferent: **CN7
10
Q
CN7 Facial nerve
A
- Muscles of facial expression
- Frowning (upper face: Frontalis)
- Blow cheek (lower face: Buccinator) - Taste of anterior 2/3 tongue
- Saliva (Submandibular + Sublingual) + Lacrimal secretion
- UMN vs LMN weakness
- upper face **bilateral innervation
- lower face **contralateral Innervation
—> UMN lesion: Upper face not affected, Lower face contralateral paresis
—> LMN lesion: Upper + Lower face ipsilateral paresis
11
Q
CN8 Vestibulocochlear nerve
A
- Rinne’s test —> Conductive deafness
- ear wax
- middle ear damage - Weber’s test —> Sensorineural deafness
- CN8 injury
- tumour
12
Q
CN9 Glossopharyngeal nerve
A
- Soft palate
- Pharynx
- Ear canal
- Sensory
- ***Parotid salivation
- Taste and sensation ***posterior 1/3 tongue
- Position + Movements of soft palate and uvula
- ***Gag reflex (afferent CN9, efferent CN10)
13
Q
CN10 Vagus nerve
A
- Pharynx
- Larynx
- Viscera
- Somatic
- Autonomic function
- GI tract - Motor function
- pharynx + larynx
- vocal cord - Sensory
- Gag reflex (afferent **CN9, efferent **CN10)
14
Q
CN11 Accessory nerve
A
- SCM
- rotate head to opposite side - Trapezius
- shrug shoulders against resistance
15
Q
CN12 Hypoglossal nerve
A
Intrinsic + Extrinsic tongue muscle (except Palatoglossus: CN10)
- Atrophy
- Fibrillation
- Deviate on protrusion
- Tongue movement
- Power
16
Q
Arms and Legs
A
Motor system
- Inspection
- Tone
- Power (MRC scale: 3: against gravity but not resistance, 2: not against gravity)
- Reflexes
- Sensation
- Coordination
Sensory system
- Spinothalamic system: Pinprick, Warmth, Fine touch
- Dorsal column: Proprioception, Vibration, Sensation
17
Q
Motor examination of arms
A
- Wasting / Muscle bulk
- distribution - Fasciculation (LMN sign) / Scars / Tremor
- Posture / Movement
- Muscle tone
- elbow
- wrist
- normal / hypotonia / hypertonia (rigidity / spasticity)
Rigidity: increased resistance throughout movement —> **Extrapyramidal
—> Lead-pipe
—> Cogwheel (in Parkinsonism)
Spasticity: 彈弓 resistance greater with speed of movement —> **Pyramidal (e.g. Clasp-knife spasticity)
- Pronator drift
- UMN (Pyramidal) weakness —> downward pronator drift
- ***Ataxia (loss of cerebellar coordination) —> upward pronator drift
- Loss of proprioception —> a searching movement that usually affects only the fingers (can be in any direction) - Muscle power (MRC scale: 0-5)
- Shoulder abduction (**C5-6)
—> Deltoid
—> **Axillary nerve - Elbow flexion (**C5-6)
—> Biceps
—> **Musculocutaneous nerve - Elbow extension (C7-8)
—> Triceps
—> ***Radial nerve - Wrist + Finger extension (**C6-8)
—> Extensor carpi radialis longus, Extensor carpi ulnaris, Long finger extensors
—> **Radial nerve - Hand grip (**C8-T1)
—> Long finger flexors, Small hand muscles
—> **Median + ***Ulnar nerve
Ulnar nerve:
- Dorsal interossei: finger ABduction
- Palmar interossei: finger ADduction
Median nerve (Thumb):
- Abductor pollicis brevis: thumb ABduction
- Opponens pollicis: thumb OPposition
- Reflex
- Biceps, Supinator jerk: **C5-6
- Triceps jerk: **C7-8
- Finger jerk: **C8-T1
- Hoffmann sign for **C8-T1 hyperreflexia - Coordination
- Finger-nose test
- Rapid alternating movements
18
Q
Motor examination of legs
A
- Wasting / Muscle bulk / Leg length discrepancy / Pes cavus
- distribution - Fasciculation / Tremor
- Posture / Movement
- Muscle tone
- hip, knee, ankle
- normal / hypotonia / hypertonia (rigidity / spasticity)
—> knee clonus
—> ankle clonus
Rigidity: increased resistance throughout movement —> **Extrapyramidal
Spasticity: 彈弓 resistance greater with speed of movement —> **Pyramidal
- Power
- Hip flexion (**L2-3)
—> Iliopsoas
—> **Nerve to Iliopsoas
- Hip extension (**L4-5, S1)
—> Gluteus
—> **Gluteal nerve - Hip adduction (**L3-4)
—> Hip adductors
—> **Obturator nerve - Hip abduction (**L5-S1)
—> Gluteal medius, Tensor fascia lata
—> **Superior Gluteal nerve - Knee extension (**L3-4)
—> Quadriceps femoris
—> **Femoral nerve - Knee flexion (**L5-S1)
—> Hamstrings
—> **Sciatic nerve - Ankle dorsiflexion (**L4-5)
—> Toe extensors
—> **Peroneal nerve - Ankle plantar flexion (**S1-2)
—> Toe flexors
—> **Popliteal nerve
- Reflexes
- Knee jerk: L3-4
- Ankle jerk: S1-2
- Plantar response down-going
- Upgoing plantar response = Babinski sign for UMN lesion - Coordination
- Heel-shin
- Heel-toe gait - Gait
- Antalgic
- Hemiplegic
- ***Wide based ataxic: Cerebellar disorder
- Shuffling, lack of arm swing: Parkinsonism
- Turn around: Bradykinesia, Postural instability, Freezing in Parkinsonism
19
Q
***UMN signs
A
- Spastic paralysis
- Little atrophy
- Hyperactive reflexes
- Clonus
- Babinski’s sign (lower limb) / Hoffman’s sign (upper limb)
20
Q
***LMN signs
A
- Flaccid paralysis
- Early-onset atrophy
- Reduced reflexes
- Fasciculations + Fibrillation
21
Q
Sensory examination of arms / legs
A
Spinothalamic
- Pinprick / Pain
- Light touch
- Temperature
Dorsal column
- Joint position: thumb / big toe movement
- Vibration: tuning fork 128Hz
22
Q
Bedside case
A
- Reduced pinprick sensation on left side whole body
- Past pointing + Heel shin intentional tremor on both sides —> Bilateral cerebellar signs
- Left facial weakness
Multiple sclerosis —> Repeated attacks
