NRE/NLE Step 1: Neurology Made Simple – Pass with Precision

Neurology can be hard, but I made it super easy for you! Just read this blog 2 or 3 times, and you’ll understand it. I made everything as simple as possible—you’re going to love it!

1. Huntington’s Disease (HD)

1. What is it?

A brain disorder that causes strange body movements, like dancing movements.

2. How it spreads?

It is a autosomal dominant and runs in families. The problem is on chromosome number 4 with too many CAG repeats in a gene.

3. What is anticipation?

The disease starts earlier and is worse in the next generation. like more it pass will become severe to next generation.

6. What is the treatment?

No cure yet. Only supportive care.

2. Parkinson’s Disease

3. How to remember?

We use “TRAP” mnemonic to remember Parkinson’s Disease.

• T: Tremor (hand shaking like rolling a pill)
• R: Rigidity (stiff arms/legs, like a cogwheel)
• A: Akinesia (moves slowly)
• P: Posture problem (easy to fall)

How Levodopa and Carbidopa Work

• Levodopa is the main medicine. It helps make dopamine in the brain.
• If we give Levodopa alone, a body enzyme called dopa decarboxylase enzyme (outside the brain) changes it too early. Carbidopa is added to protect Levodopa in the body.
• Carbidopa stops Levodopa from working before it reaches the brain.
• Carbidopa cannot enter the brain (it stops at the brain barrier).
• Levodopa goes into the brain and then works to fix low dopamine.

Think of it like this:
Carbidopa is a bodyguard that keeps Levodopa safe until it reaches the brain.
Once inside, Levodopa does its job.

3. Neuromuscular Junction Disorders

1. Myasthenia Gravis

In Myasthenia Gravis, the body makes anti-Ach receptor antibodies that block the Ach (acetylcholine) receptors at the muscles.
This stops the message from the nerve to the muscle, so the muscles become weak.

• In the morning, the person feels okay.
• By evening, they feel very tired.
• Working or moving makes the weakness worse.
• Ocular symptoms are present.

Eye symptoms (ocular signs)

Linked with

• Thymoma – A tumor in the thymus gland

2. Lambert-Eaton Syndrome

Calcium is needed to release Ach from Axon. In Lambert eaton syndrome anti-calcium channel antibodies are formed and it act on the calcium channel and wont allow to release Ach. Simply no calcium no ach. In morning they are very tired but with movement they become better. There is no ocular symptoms.

Linked with

• Small Cell Lung Cancer

Diagnosis

• Myasthenia gravis is diagnosed by edrophonium (Tensilon) test and anti-Ach receptor antibodies.
• Lambert eaton syndrome is diagnosed by edrophonium test.
• Edrophonium temporary decreases Ach esterase (ach breaker) and will increase Ach.

Treatment

Pyridostigmine – keeps more Ach in the junction to improve strength.

Feature	Myasthenia Gravis	Lambert-Eaton Syndrome
Cause	Anti-Ach receptor antibodies	Anti-calcium channel antibodies
Weakness Pattern	Worsens with activity	Improves with activity
Ocular Symptoms	Ptosis, Diplopia	None
Linked with	Thymoma	Small Cell Lung Cancer
Diagnosis	Edrophonium Test, Anti-Ach Test	Anti-Calcium Channel Test

3. Location of Cell Death According To Disease

1. Parkinson’s Disease: Substantia nigra is damaged. Dopamine goes down and acetylcholine (Ach) goes up.
2. Alzheimer’s + dementia Disease: Effects the temporal lobe. Ach and norepinephrine go down.
3. ALS (Amyotrophic Lateral Sclerosis): Destroys spinal cells. Both upper and lower motor nerves are affected. Treatment: Riluzole
4. Myasthenia Gravis: The body blocks Ach receptors → muscles become weak.
5. Lambert-Eaton Syndrome: The body makes antibodies against calcium channels (Anti-cac).

4.Tremors (Shaking)

Older People – Resting Tremor	Younger People – Essential Tremor
Unilateral tremors	Bilateral tremors
Tremors decrease with movement	Tremors decrease with movement
Seen in Parkinson’s.	Family history positive
	Treatment: Propranolol Side Effects: 1. Can cause breathing trouble (bronchoconstriction) 2. Can hide signs of low sugar (hypoglycemia) Do Not Use In: 1. Asthma 2. Diabetes

Fine Tremor:
Can be caused by Graves’ disease (hyperthyroidism).

5. Intracerebral Hemorrhage (ICH)

The brain is covered by 3 protective layers called meninges:

Types of Brain Bleeding (Hemorrhage)

There are three types of bleeding occur in brain

1. Epidural Hemorrhage
2. Subdural Hemorrhage
3. Subarachnoid Hemorrhage

1. Epidural Hemorrhage

• Blood collects in the epidural space
• Cause: Middle meningeal artery tear (often from skull fracture)
• Lucid interval: Person wakes up then goes unconscious
• CT scan: Looks like a biconvex (lens-shaped) bleed

2. Subdural Hemorrhage

Feature	Epidural Hemorrhage	Subdural Hemorrhage
Location	Epidural space (between skull and dura)	Subdural space (between dura and arachnoid)
Primary Cause	Tear of middle meningeal artery (often from skull fracture)	Tear of bridging veins (common in elderly or after trauma)
Lucid Interval	Classic “wake-up” then rapid decline	May be absent or subtle, variable timing
CT Scan Appearance	Biconvex (lens-shaped) hyperdensity	Biconcave (crescent-shaped) hyperdensity

3. Sub-arachnoid Hemorrhage (SAH)

1. Bleeding collects in the subarachnoid space (Circle of Willis)
2. Cause: Rupture of berry aneurysm (small weak spot in artery)
3. Most common at: Where Internal Carotid meets Anterior Communicating Artery

Symptoms:

1. Sudden severe headache (“worst headache of life”)
2. Vomiting, nausea, confusion (ALOC = altered level of consciousness)

Linked to:

1. Autosomal Dominant
2. Polycystic Kidney Disease

Treatment:

1. Beta blockers (Labetalol) – to control blood pressure
2. Calcium channel blockers (Nimodipine) – to prevent vessel spasm

Extra Notes:

1. Vertebral artery passes through the foramen magnum (big hole at the base of the skull).
2. Internal carotid artery passes through the foramen lacerum (a smaller hole near the base of the skull).

6. Multiple Sclerosis (MS)

An immune-mediated disease that attacks the central nervous system (CNS) and damages the myelin sheath (the protective covering of nerves).

Symptoms

Remember the mnemonic “SIN“

• S – Scanning speech (broken, choppy speech)
• I – Intention tremor (tremor increases during movement)
• N – Nystagmus (eye shaking) → can cause diplopia (double vision)

Diagnosis

• Investigation of choice: MRI (shows white matter plaques)
• Diagnostic criteria: McDonald’s Criteria

Treatment

1. First-line: Oral corticosteroids
2. If no response: Plasma exchange (plasmapheresis)
3. If optic neuritis (eye involvement):
   Start with IV steroids, then oral steroids, then plasmapheresis

New Therapy

• Ocrelizumab – a monoclonal antibody used in MS treatment           

7. Guillain-Barré Syndrome (GBS) / Acute Inflammatory Polyneuropathy

A sickness where the body attacks its own nerves (auto immune). It causes weakness that starts in the legs and moves up (ascending paralysis).

Causes

• Often happens after a stomach infection (gastritis or campylobacter jejuni)

Symptoms

• Starts about 1 week after the infection
• Legs feel weak, then arms
• Reflexes (like knee-jerk) are slow or gone

Diagnosis

• EMG: Shows slow nerve conduction
• Anti-Ganglioside (anti-Schwann) antibodies may be present

Treatment     

• Plasma exchange
• IVIG (good antibodies through a drip)
• Ventilator if diaphragm is affected
• Steroids don’t help

8. Amyotrophic Lateral Sclerosis (ALS) / Lou Gehrig’s Disease

What is ALS?

ALS is a sickness that hurts the nerves that help your muscles move. These nerves come from the brain and spine.

What happens in ALS?

Two types of nerves stop working:

Other Problems:

• Trouble swallowing food
• Hard to move the tongue

Treatment:

There is no full cure, but a medicine called Riluzole helps slow it down.

9. Headache

Headache Types

There are 2 main types of headache:

Feature	Cluster Headache	Migraine	Tension Headache
Pain Location	Periorbital (around one eye)	Unilateral (one side of head)	Diffuse, tight “band-like” around head
Associated Signs	Red eyes, tearing (lacrimation)	Photophobia, phonophobia (light/sound worsens pain)	None typically beyond aching muscle tension
Triggers/Relief	Prefer dark, quiet environment	Rest in a dark room	Rest or cessation of activity
Onset/Pattern	Short attacks (15–180 min), several per day, often at night	Hours to days, may have prodrome or aura	Gradual onset, related to stress or posture
Treatment	High-flow oxygen, NSAIDs, triptans; sometimes prophylactic Vitamin D₃	NSAIDs, triptans, antiemetics, rest in dark room	NSAIDs, relaxation techniques, stress management

10. Seizure

A seizure happens when brain cells (neurons) become too active (excite)that lead to muscle contraction. This can make the body shake or jerk.

Types of Seizure

1. Partial Seizure (only a part of the brain):
   • Simple Seizure: The person is awake with seizure.
   • Complex Seizure: The person is confused or not awake with seizure. Often starts in the temple part of the brain.
2. Generalized Seizure (whole brain):
   • Affects both sides of the brain.
   • Person passes out (ALOC) with seizure.
3. Tonic-clonic seizure:
   • ALOC, back extend and muscle constrict.
   • Bite tongue and pee without knowing (urine incontinence).
4. Absence Seizure (common in children):
   • Child stares or blanks out for 5–10 seconds.
   • No shaking.
5. Status Epilepticus (vey long seizure)
   Lasts more than 5 minutes – very dangerous.
   • Give benzodiazepines and fosphenytoin.
   • May need to ventilate

Diagnosis

We do a test called EEG to look at brain activity.

Treatment

1. Secure the airway so they can breathe.
2. Medicines called antiepileptics help stop seizures.

Medicine Tips

• Valproic acid is the liver toxic.
• Phenytoin blocks sodium channel (Na) – helps stop seizures also it is a anti arrhythmic drug.
  • Phenytoin side effects:
  • Swollen gums (Gingival hyperplasia).
  • Megaloblatic Anemia.
  • Also works as a antiarrythemic.
• Antiepileptics (hepatotoxic) medicines can cause low folate:
  • Can lead to spina bifida (a birth problem).
  • Can cause megaloblatic anemia (low blood).
• Best drug for absence seizure: Ethosuximide

11. Dementia

Types of Dementia

1. Alzheimer’s Disease

• Most common kind.
• Brain gets smaller and ventricles (fluid spaces) get bigger.
• Senile Plaques (bad proteins) build up in the brain.
• Symptoms: Forgetting things, trouble thinking, confusion.
• Medicines: Donepezil, Galantamine.

2. Normal Pressure Hydrocephalus (NPH)

• Brain’s fluid spaces (ventricles) get bigger (ventriculomegaly), but fluid pressure stays normal.
• Brain may shrink.
• Main signs:
  • Ataxia (Walking problems)
  • Dementia
  • Urinary incontinence

Feature	Alzheimer’s Disease (AD)	Normal Pressure Hydrocephalus (NPH)
CSF Absorption	CSF fluid doesn’t absorb well	Normal CSF absorption
Ventricles	Ventricles grow due to poor CSF absorption	Ventricles stay enlarged, but CSF pressure is normal
Brain Changes	Brain shrinks (especially in the hippocampus and cortex)	Brain may shrink, but ventricles remain enlarged
CSF Pressure	Pressure may fluctuate or be abnormal	CSF pressure is normal
Clinical Signs	Memory loss, confusion, cognitive decline, and personality changes	Gait disturbance, urinary incontinence, and cognitive decline

3. Lewy Body Dementia

• Dementia with hallucinations (seeing or hearing things that aren’t real).

4. Frontotemporal Dementia (Pick’s Disease)

• Front and temporal parts of the brain decrease in size.
• Causes behavior changes like acting oddly or saying strange things.
• Dementia

5. Memory Loss (Amnesia)

• Happens suddenly, often after a head injury or stress.

Types of Amnesia:

• Retrograde Amnesia:
  • Can’t remember things before the accident.
• Anterograde Amnesia:
  • Can’t remember things after the accident.

6. Vascular Dementia

• Second most common type of dementia.
• Happens after many strokes with dementia and multiple infarction.

7. Creutzfeldt-Jakob Disease (CJD)

• Demenntia that comes very suddenly.
• Caused by prion proteins (bad proteins) in the brain.

12. Stroke

• A stroke happens when blood can’t reach the brain.
• Middle cerebral artery is affected that is the branch of internal carotid artery.
• This causes brain damage and problems like moving, talking, or seeing.

Types of Stroke:

• Ischemic Stroke (80–85%): A block in the blood vessel.
• Hemorrhagic Stroke (10–15%): A burst in the blood vessel causing bleeding.

Stroke Risk Factors

Things that make stroke more likely remember by this mnemonic ‘LPDS’

• L: Hyper lipidemia (High cholesterol)
• P: Pressure of blood increases
• D: Diabetes
• S: Smoking

Arteries Affected in Stroke & Symptoms

1. MCA (Middle Cerebral Artery) block
   • Half body weakness, trouble speaking, face droops.
   • Use ‘F.A.S.T’ mnemonic:
     • Face: Is it drooping?
     • Arm: Can they lift both arms?
     • Speech: Is speech slurred?
     • Time: Call an ambulance fast!
2. PCA (Posterior Cerebral Artery) block
   • Stroke with vision problems.
3. ACA (Anterior Cerebral Artery) block
   • Stroke with leg or lower body weakness.

Stroke Treatment

• If patient comes within 4 hours:
  • Give TPA (Thrombolytics – a medicine to break the clot).
• If later than 4 hours:
  • Give Aspirin (stops more clots by blocking TXA2).

13. Aphasia – Trouble Speaking or Understanding

1. Broca’s Aphasia (Motor/Expressive Aphasia)

• Where in brain: Front part (frontal lobe), MCA area.
• What happens:
  • Person understands what you say.
  • But they can’t speak clearly or make full sentences.
  • They know what they want to say but can’t get the words out.

2. Wernicke’s Aphasia (Sensory/Receptive Aphasia)

• Where in brain: Side part (temporal lobe), MCA area.
• What happens:
  • Person can talk, but the words don’t make sense.
  • They don’t understand what others are saying.

14. Brain Tumors (Neoplasms)

Primary Brain Tumors by Age

In Adults:

• Glioblastoma Multiforme (GBM)
  • Very fast-growing and dangerous.
  • Malignant.
  • Bad outlook (poor prognosis).
  • Life less than 1 year.
• Meningioma
  • Grows slowly.
  • Headache and accidently diagnose.
  • Usually not dangerous (good prognosis).

In Children:

• Astrocytoma
  • Common and may be less severe.
• Medulloblastoma
  • More aggressive.
  • Needs fast treatment.

1. Acoustic Neuroma (Cranial Nerve 8 Tumor)

• Also called Vestibular Schwannoma.
• Seen in Neurofibromatosis Type 2.
• Affects Cranial Nerve 8, which helps with hearing and balance.

Symptoms:

• Hearing loss on one side.
• Ringing in the ears (tinnitus).
• Feeling dizzy or off balance (vertigo).

2. Medulloblastoma

• Common in children.
• Grows near the 4th ventricle in a part of the brain called the cerebellar vermis.

Symptoms:

• Blocks fluid in the brain → causes hydrocephalus (CSF buildup).
• Increased pressure in the head – intracranial pressure (ICP) (causing headache, vomiting).

3. Craniopharyngioma

• A tumor found above the pituitary gland (suprasellar area) Supra cellular tumor.
• Often shows calcium spots on X-rays or CT.

Symptoms:

• Calcium deposit on the optic chiasm (vision nerve crossing).
• Causes bitemporal hemianopia (can’t see side vision on both eyes).

4. Astrocytoma

• A brain tumor made from astrocyte cells.
• Test marker: GFAP (Glial Fibrillary Acidic Protein).

5. Oligodendroglioma

• A tumor made from oligodendrocytes (oligodendrocytes makes myelin shealth).
• Usually slow-growing and found in adults.