Approach to the Headache:
Primary vs Secondary, and Intracranial vs Extracranial:
Intracranial–Pain sensitive structures in the brain includes venous sinuses, cortical veins, basal arteries, dura of anterior, middle, and posterior fossae.
Extracranial—Scalp vessels and muscles, orbital contents, mucous membranes of nasal and paranasal spaces, external and middle ear, teeth, and gums.
- Tension: Most common, diffuse, dull, band-like headache, worse when touching scalp. May become worse towards the end of the day, aggravated by noise. Mechanism: muscular due to contraction of jaw, teeth, brow. Tx: Amitriptyline and tricyclic antidepressants or β blockers.
2. Migraine: Unilateral throbbing headache, onset in childhood or early adult life. Affects 5-10% of population, with female predominance and has family history. With or without aura (flashing lights, zigzags, scintillating scotoma, visual field defects), worsened by bright light, relieved by sleep, associated with nausea and occasionally vomiting. Some types of migraine (Basilar, Hemiplegic, retinal) may be associated with severe symptoms such as tetraparesis or hemiparesis, unsteadiness, dysarthria, vertigo, bilateral visual symptoms.
May go through phases: Premonition or prodromalà Aura à Headache àResolution.
Diatary: alcohol, chocolate, cheese (contains tyramine)
Hormonal: Premenstrual or oral contraceptive (fluctuating oestrogen)
Stress, physical fatigue, exercise, sleep deprivation and minor head trauma.
D/D with: Partial epilepsy, transient ischemic attack, arteriovenous malformation, hypoglycemia.
Tx: Analgesics, sumatriptan, ergotamine, prophylaxis (5HT2 receptor blocker Pizotifen, or propranolol (beta adrenergic receptor blocker)), calcium antagonists (verapamil), antipressants (amitriptyline), anticonvulsants (topiramate or sodium valproate).
- Cluster: (Histamine cephalgia, migrainous neuralgia) Often in men in middle age, severe unilateral pain lasting 10 mins to 2 hours around the eye, associated with conjunctival injection, lacrimation, rhinorrhea, and transient Horner’s (miosis, ptosis, anhidrosis). Alcohol may precipitate.
- Sinus headache
- Medication overuse
- Meningitis and other infections
- Intracranial hypotension
- Increased intracranial hypertension
- Brain tumor or aneurysm
- Cervicogenic headache
- Temporal arteritis
- Acute close angle glaucoma
Differentiate using the SNOOP list:
- Systemic Signs or Symptoms: Look for the presence of fever, weight loss, history of cancer, abnormal blood tests; this could point to meningitis, cancer, or illness to be the cause of the headache.
- Neurologic Exam: if the neurologic exam is abnormal, then consider secondary headache as the cause. Eg: abnormal speech, gait, confusion, and dizziness.
- Onset: Sudden, abrupt, or split-second.
- Onset: if less than age 5 or new onset greater than 50 years old
- Progressive: this would refer to a headache pattern that is progressively worsening over time. (Or previous headache history).
Reassuring history of a primary headache:
- Stable pattern of headache for over 6 months
- Predictable triggers for a headache
- Individual feels fine between attack
2. Assessment of upper extremities:
Observe: For muscle wasting, fasciculations, asymmetry, or walkers and other assistant devices beside the bed.
Tone and Clonus:
Tone may be increased due to UMN lesion (Spasticity), or due to extrapyramidal tract (Rigidity). It can also decrease due to LMN lesions (Flaccidity). Tested by supporting elbow and shaking hand, then rapidly supinate and pronate arm. Test spasticity by flexion of elbow and watch for cogwheel or clasp knife.
Abduct arm >90 degrees; Deltoid ; Axillary n.; C5-6
Elbow flexion: Biceps, brachialis; Musculocut. n.; C5-6
Wrist flexion: Flexor carpi radialis; median n.; C6-7
Finger Flexion: Flexor digitorum profundus; ulnar n.; C7-8
Finger extension: Extensor digitorum or extensor digiti minimi; Radial n.; C7-8
Wrist extension: Extensor carpi radialis, Radial n.; C7-8
Elbow extension: Triceps; Radial nerve; C7-8
Finger ADDUCTION: Adductor policis, Ulnar n.; V8, T1
Finger ABDUCTION: Abductor pollicis brevis; median n.; C8, T1
Thumb up: Abductor pollicis longus + brevis, Ulnar nerve, C8, T1
3. Assessment of Lower Extremities:
Tone: Logroll, flex and extend the knee.
Rapid dorsiflexion: ankle clonus
Hip flexion: ilio-psoas; Femoral n.; L2-3
Knee extension: Quadraceps; Femoral n.; L3-4
Foot dorsiflexion: Tibialis anterior; Deep peroneal n.; L4-5
Foot plantarflexion: Gastrocnemius, Soleus; Tibial n.; S1-2
Knee Flexion: Hamstrings; Sciatic n.; L5-S1
Hip Extension: Gluteus max; Inferior gluteal n,; L5-S1,2
Hip Adduction: Adductors; Obturator n.; L2-3-4
Hip abduction: Gluteus med + Min+ tensor fascia latae; Sup. Gluteal n,; L4-5 S1
Eversion: Peroneus longus + brevis; Superficial peroneal n.; L5-S1
Inversion: Tibialis posterior; Tibial n.; L5-S1
Toe extension: Ext. hallucis longus, ext. digitorum longus; Deep peroneal n.; L4-5
4. Descending Tracts:
- Start from primary motor, premotor, and supplementary motor, as well as somatosensory area
- Descends through internal capsule
- Through crus cerebri of midbrain, to pons and medulla
- Divides into Lateral and Anterior tracts
- Anterior corticospinal tract remains ipsilateral
- Lateral corticospinal tract descends contralaterally to ventral horn and to lower motor neuron.
- Primary motor cortex (lateral)
- Brain stem
- Cranial nerves
- Face and neck (Bilateral innervation except 7 and 12)
- Vestibulospinal Tracts: Vestibular nuclei, receives input from organs of balance, controls ipsilateral balance and posture, anti-gravity muscles.
- Reticulospinal Tracts: Medial RST arise from pons, facilitates voluntary movements and increase muscle tone, lateral RST arises from medulla, and inhibits voluntary movements, and reduce muscle tone.
- Rubrospinal Tracts: Originates from red nucleus in midbrain, they decussate and descend with contralateral innervation, plays a role in fine control of hand movements.
- Tectospinal Tracts: Begins at superior colliculus of midbrain, receives input from optic nerves, coordinates movements of the head in relation to visual stimuli.
5. Ascending Tracts:
- Dorsal column medial lemniscus pathway:
DCML: Sensory, tactile (fine touch), vibration, proprioception.
1o Upper limb signals (T6 and above)- Fascicus cuneatus (lateral), synapse at nucleus cuneatus of the medulla oblongata. (Lower limb signals below T6 go in the fasciculus gracilis (medial), and synapse at nucleus gracillis)
2o Cuneate or gracilis nucleus dicussate at medulla, travel in the contralateral medial lemniscus and reach the Ventral posterolateral nucleus of thalamus.
3o At VPL nucleus it goes through internal capsule to sensory cortex.
- Anterolateral system (Spinothalamic tract):
Lateral spinothalamic tract (Pain and temperature)
Anterior spinothalamic tract (touch and pressure)
1o Skin to dorsal spinal cord, ascend 1 or 2 levels via Lissauer’s tract, to synapse at tip of dorsal horn called Substantia Gelatinosa.
2o Substantia gelatinosa: Decussates at anterior white commissure and goes to VPL nucleus of thalamus.
3o From VPL nucleus to the sensory cortex.
Unconscious Tracts: Spinocerebellar tracts:
- Posterior (lower limbs)
- Anterior (lower limbs)
- Rostral (Upper limbs)
- Cuneocerebellar (Upper limbs)