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ELECTRO
ENCEPHALO
GRAPHY
:- To check the records of brain waves, and to detect the level of electrical activity in the brain is
called EEG
The "10-20 System" of Electrode PlacementThe "10-20 System" of Electrode Placement
The 10-20 System of Electrode Placement is a method used to describe the location of scalp electrodes. These scalp electrodes are used to record the electroencephalogram (EEG) using a machine called an electroencephalograph. The EEG is a record of brain activity. This record is the result of the activity of thousands of neurons in the brain. The pattern of activity changes with the level of a person's arousal - if a person is relaxed, then the EEG has many slow waves; if a person is excited, then the EEG has many fast waves. The EEG is used to record brain activity for many purposes including sleep research and to help in the diagnosis of brain disorders, such as epilepsy.
One second of EEG signal
Historically four major Historically four major types of continuous types of continuous rhythmic sinusoidal rhythmic sinusoidal
EEG waves are EEG waves are recognized recognized
(alpha, beta, delta and (alpha, beta, delta and theta).theta).
•Alpha (Berger's wave):-:-The frequency range from (8 The frequency range from (8 Hz to 13 Hz). It is characteristic of a relaxed, alert state of consciousness . Alpha rhythms are best detected with the eyes closed. Alpha attenuates with drowsiness and open eyes, and is best seen over the occipital (visual) cortex.
•Beta :-
The frequency range 13-30 Hz. Low amplitude beta The frequency range 13-30 Hz. Low amplitude beta with multiple and varying frequencies is often with multiple and varying frequencies is often associated with active, busy or anxious thinking and associated with active, busy or anxious thinking and active concentration. Rhythmic beta with a dominant active concentration. Rhythmic beta with a dominant set of frequencies is associated with various set of frequencies is associated with various pathologies and drug effects. pathologies and drug effects.
Delta:-
The frequency range up to 4 Hz and is often The frequency range up to 4 Hz and is often associated with the very young and certain associated with the very young and certain encephalopathies and underlying lesions. It is seen in stage 3 and 4 sleep.
•Theta:- The frequency range from 4 Hz to 8 Hz and is associated The frequency range from 4 Hz to 8 Hz and is associated with drowsiness, childhood, adolescence and young with drowsiness, childhood, adolescence and young adulthood. This EEG frequency can sometimes be adulthood. This EEG frequency can sometimes be produced by produced by hyperventilation. Theta waves can be seen . Theta waves can be seen during during hypnagogic states such as trances, states such as trances, hypnosis, deep , deep day dreams, day dreams, lucid dreaming and light and light sleep and the and the preconscious state just upon waking, and just before preconscious state just upon waking, and just before falling asleepfalling asleep.
Some examples of EEG waves.Some examples of EEG waves.
THE BASIC PRINCIPLES OF EEG DIAGNOSISTHE BASIC PRINCIPLES OF EEG DIAGNOSIS
What abnormal results mean What abnormal results mean
Seizure disorders (such as epilepsy or convulsions) Seizure disorders (such as epilepsy or convulsions) Structural brain abnormality (such as a brain tumor or Structural brain abnormality (such as a brain tumor or
brain abscess) brain abscess) Head injury, encephalitis (inflammation of the brain) Head injury, encephalitis (inflammation of the brain) Hemorrhage (abnormal bleeding caused by a ruptured Hemorrhage (abnormal bleeding caused by a ruptured
blood vessel) blood vessel) Cerebral infarct (tissue that is dead because of a blockage Cerebral infarct (tissue that is dead because of a blockage
of the blood supply) of the blood supply) Sleep disorders (such as narcolepsy) Sleep disorders (such as narcolepsy)
Note:- Note:- EEG may confirm brain death in someone who is in a comaEEG may confirm brain death in someone who is in a coma..
ATYPICAL BUT NORMAL WAVE FORMSATYPICAL BUT NORMAL WAVE FORMS
K ComplexesK Complexes
K Complexes occur in sleep when arroused - thus K complexes are seen with noises or other stimuli especially in stage 2 sleep. The K complex is often followed by an arrousal response - namely a run of theta waves of high amplitude. Following this the EEG shows sleep again or the awake state.
Lambda and POSTSLambda and POSTS
Lambda and POSTS are similar morphologically, and have a triangular shape.They occur posteriorly and symmetrically. POSTS stands for 'positive occipital transients of sleep' and occurs in stage 2 sleep. Lambda occurs in the awake patient when the eyes stare at blank surfaces. Both are normal wave forms and can occur singly or inlong or short runs.
V Waves
V waves occur in the parasaggital areas of the two sides and take the form of sharp waves or even spikes which show in the biparietal regions(vertex) withphase reversal at the midline in tranverse montages or at the vertex in front-to-back ones. They are seen in stage 2 sleep along with spindles, K complexes, POSTS, etc..
MU activity
Mu activity is a rhythm in which the waves have a shape suggestive of a wicket fence with sharp tips and rounded bases. It may show phase reversal between two channels. The frequency is generally half of the fast activity present.
Psychomotor VariantPsychomotor Variant
Psychomotor variant is a rare rhythm which appears to be an harmonic of two or more basic rhythms causing a complex form. As can be seen it is higher in amplitude than the surround and the waves have a notched appearance. It is quite assymetrical and is often mistaken for paroxysmal activity. It is benign. It is also known as
Fourteen and Six RhythmFourteen and Six Rhythm
Fourteen and six activity is most often seen in children and adolescents. As seen it takes the form of 6 Hz and 14 Hz waves sometimes going in the same direction(up or down) and in others in opposite directions. It is typically seen in sleep or drowsiness and is usually seen in monopolar recordings.
ELECTROELECTRO
MIOMIO
GRAPHYGRAPHY
Amplifier parameters Channels
Sensitivity Scaling for analysis
fo fu 50 Hz notch Rctf. Ext.Input
Auto-matic offset
Spontanous 1 0,1 mV/div 0,1 mV/div 10 kHz 5 Hz x x
MAP-Analyse 1 0,1 – 0,2 mV/div 0,1 mV/div 10 kHz 5 Hz x x
Maximal-innervation 1 1 mV/div 1 mV/div 10 kHz 5 Hz x x
Aquisition-parameters
Monitor time Analysis time Trigger-mode Averagermode
Sweeps (no. of passes) ArtefactDetection
Spontan-aktivität 10 ms/div 10 ms/div Internal Standard --- ---
MAP-Analyse 10 ms/div 10 ms/div Internal Standard --- ---
Maximal-innervation
100 ms/div 100 ms/div Internal Standard --- ---
An electromyogram (EMG) is a test that is used to record the electrical activity of muscles. When muscles are active, they produce an electrical current. This current is usually proportional to the level of the muscle activity.
EMGs can be used to detect abnormal muscle electrical activity that can occur in many diseases and conditions, including muscular dystrophy, inflammation of muscles, pinched nerves, peripheral nerve damage.
The EMG helps to distinguish between muscle conditions in which the problem begins in the muscle and muscle weakness due to nerve disorders. The EMG can also be used to detect true weakness, as opposed to weakness from reduced use because of pain or lack of motivation.
NEEDLE EMG CRANIAL MUSCLESNEEDLE EMG CRANIAL MUSCLES
Frontalis
Masseter
Orbicularis Oculi
Orbicularis Oris
Sternocleidomast
oid
Tongue -
Genioglossus
Trapezius
NEEDLE EMG | FOOT MUSCLESNEEDLE EMG | FOOT MUSCLES
Abductor Digiti Quinti - Foot
Abductor Hallucis
Extensor Digitorum Brevis
First Dorsal
Interosseous - Foot
NEEDLE EMG | FOREARM MUSCLESNEEDLE EMG | FOREARM MUSCLES
Anconeus
ANCONEUS
EXTENSOR DIGITORUM COMUNIS
BRACHIORADIALIS
EXTENSOR CARPI RADIALIS (Lt.)
EXTENSOR INDICIS
FLEXOR CARPI RADIALIS (Rt.)
FLEXOR CARPI ULNARIS
SUPINATOR
FLEXOR DIGITORUM PROFUNDUS
FLEXOR POLLICIS LINGUS
PRONATOR TERES
NEEDLE EMG | HAND MUSCLESNEEDLE EMG | HAND MUSCLES
ABDUCTOR POLLICIS BRAVIS
FIRST DORSAL INTEROSSEOUS
ABDUCTOR DIGITI MINIMI (HAND)
NEEDLE EMG | LEG MUSCLESNEEDLE EMG | LEG MUSCLES
EXTENSOR HALLUCIS LONGUS
GASTROCNEMIUS (MEDIAL HEAD)
EXTENSOR DIGITORUM LONGUS
ANTERIOR TIBIAL
SOLEUS
PERONEAL LONGUS
GASTROCNEMIUS
NEEDLE EMG | PARASPINAL MUSCLESNEEDLE EMG | PARASPINAL MUSCLES
Multifidus - Rostral Insertion
Multifidus - Perpendicular
Insertion
Multifidus - Caudal Insertion
NEEDLE EMG | ARM AND SHOULDER MUSCLESNEEDLE EMG | ARM AND SHOULDER MUSCLES
BICEPS BRACHLI
DELTOID (MIDDLE)
DELTOID (ANTERIOR)
INFRASPINATUS
LEVATOR SCAPULA
Pectoralis Major - Clavicular
Pectoralis Major - Sternocostal
RHOMBOID (MAJOR)
RHOMBOID (MINOR)
SUPRASPINATUS
SERRATUS ANTERIOR
TRICEPS BRACHII (LONG HEAD)
TRICEPS BRACHII (Lateral head)
NEEDLE EMG | THIGH AND PELVIS MUSCLESNEEDLE EMG | THIGH AND PELVIS MUSCLES
LLIACUS
GULUTEUS MEDIUS
GLUTEUS MEXIMUS
BICEPS FEMERIS
ABDUCTOR LONGUS
VASTUS MEDIALIS
VASTUS LATERALIS
Semitendinosus
Semimembranosus
NERVE
CONDUCTION
VELOCITY
:- To check the electrical activity of
nerves
Amplifier parameters
Channels Sensitivity Scaling for analysis
fo fu 50 Hz notch
Rctf. Ext. Input
Input
Motoric NCV
1 2 mV/div 2 mV/div 3 kHz 5 Hz x
Sensory NCV
1 10 µV/div 5 µV/div 3 kHz 20 Hz x x
Mot. Sens. NCV
2 2 mV/div 2 mV/div 3 kHz 20 Hz X
10 µV/div 5 µV/div 3 kHz 20 Hz
Myasthenia
1 2 mV/div 2 mV/div 3 kHz 20 Hz
Aquisition-parameters
Monitor time Analysis time Trigger-mode Averager Sweeps (no. of passes)
Artefact
mode Detection
Motoric NCV 20 ms/div 2 ms/div internal standard 20 ----
Sensory NCV 10 ms/div 2 ms/div internal standard 20 ----
Mot. Sens. NCV
20 ms/div 2 ms/div internal standard 20 1,0 ms
Myastenia 20 ms/div 2 ms/div internal standard ---- 2,0 ms
Stimulation-parameters
Stim. Ferquency
Stim. Mode Duration Stimulation current step
Traces
Motorische NLG
1,0 Hz Single puls 200 µs automatic 3
Sensible NLG 3,0 Hz Single puls 200 µs automatic 2
Mot. Sens. NLG
2,0 Hz Single puls 200 µs automatic 2
Myasthenia 3,0 Hz Single puls 200 µs automatic 10 automatic trace advance
Reflex
Amplifier parameters
Channels Sensitivity Scaling for analysis
fo fu 50 Hz notch
Rctf. Ext.Inpu
t
Auto-matic offset
Blink reflex 2 100 µV/div 100 µV/div 3 kHz 20 Hz x
H-Reflex 1 1 mV/div 1 mV/div 3 kHz 20 Hz x
F-Wave 1 200 µV/div 200 µV/div 10 kHz 5 Hz x
Aquisition-parameters
Monitor time
Analysis time Trigger-mode
Averagermode
Sweeps (no. of passes)
ArtefactDetection
Blink reflex 20 ms/div 10 ms/div internal Standard --- ---
H-Reflex 20 ms/div 10 ms/div internal Standard --- ---
F-Wave 5 ms/div 5 ms/div internal Standard 10 ---
Stimulation-parameters
Stim. Ferquency
Stim. Mode Duration Stimulation current step
Traces
Blink reflex 0,5 Hz Single puls 200 µs 0,5 mA 2
H-Reflex 0,5 Hz Single puls 500 µs Automatic 10 automatic trace advance
F-Wave 1,0 Hz Single puls 100 µs Automatic 10 automatic trace advance
Nerve conduction studies have been Nerve conduction studies have been found to be medically necessary for the found to be medically necessary for the
following indicationsfollowing indications ??
Carpal tunnel syndrome Diabetic neuropathy Disorders of peripheral nervous system Disturbance of skin sensation Fasciculation Joint pain Muscle weakness Myopathy
Nerve root compression Neuritis Neuromuscular conditions Pain in limb Plexopathy Spinal cord injury Swelling and cramps Trauma to nerves. Myositis
Major nerves of ULs (Upper Limbs) are:-
MEDIAN MOTOR / APBDistance = 5cm
Stim Points:Elbow / Wrist
MEDIAN SENSORY / IndexDistance = 8cm
Stim Points:Elbow / Wrist
ULNAR MOTOR / ADMDistance = 5cm
Stim Points:Above Elbow / Below Elbow / Wrist
ULNAR SENSORY / VthDistance = 8cm
Stim Points:Elbow / Wrist
RADIAL SENSORY / Dors HndDistance = 10cm
Stim Points:Forearm
Major nerves of LLs (Lower Limbs) are:-
PERONEAL MOTOR / EDBDistance = 7cm
Stim Points:Above/Below-Fibular Head/Ankle
PERONEAL SENSORY Distance = 14cm
Stim Points:Dist / Prox
POSTERIOR TIBIAL MOTOR Distance = 14cm
Stim Points: Pop Fossa / Ankle
SURAL SENSORY / Beh MallDistance = 14cm
Leg
H-Reflex (Soleus)
H-Reflex Potentials
NERVE ENTRAPMENT GUIDE NERVE ENTRAPMENT GUIDE PERONEAL NEUROPATHYPERONEAL NEUROPATHY
WHAT IS INVOLVEDWHAT IS INVOLVED
Peroneal Nerve
LOCATIONLOCATION
Most frequently at the Head of the Fibula
Could be just above or below it involving the Common Peroneal Nerve or the Deep or Superficial branches selectively
COMMON SYMPTOMSCOMMON SYMPTOMS
Foot drop
Patient unable to pull foot or toes up
Usually unilateral, could be bilateral
No associated pain
Main complaint is tripping, falling
Occasional leg/top of foot numbness
Symptoms always present, no night/day preference
RADIAL NEUROPATHYRADIAL NEUROPATHY (WRIST DROP)(WRIST DROP)
WHAT IS INVOLVEDWHAT IS INVOLVED
LOCATIONLOCATION
Radial Nerve
Most frequently at the Spiral Groove of the humerus
Could be at the Axilla (Saturday Night palsy)
Or in the Forearm (Posterior Interosseous Syndrome)
COMMON SYMPTOMSCOMMON SYMPTOMS
Wrist drop, Patient unable to extend wrist or fingers up
Almost always unilateral
No associated pain
Occasional forearm/hand/thumb numbness
Symptoms always present no night/day preference
NERVE SHOULDER / ARM / NERVE SHOULDER / ARM / HAND PROBLEMS HAND PROBLEMS
/TARSAL TUNNEL SYNDROME/TARSAL TUNNEL SYNDROME
WHAT IS INVOLVEDWHAT IS INVOLVED
Posterior Tibial Nerve
LOCATIONLOCATION
Posterior Tibial nerve entrapment at the Tarsal Tunnel in the foot at the level of the medial malleolous
COMMON SYMPTOMSCOMMON SYMPTOMS
Foot, Ankle, Sole pain/burning and aching
Worse at night
Occasional numbness/tingling sole of foot
No muscle weakness
Usually unilateral
Difficulty walking because of pain and discomfort with shoes
Positive Tinel (tingling upon tapping nerve) sign behind the medial malleolous
SHOULDER / ARM /HAND PROBLEMSSHOULDER / ARM /HAND PROBLEMS /ULNAR NEUROPATHY/ULNAR NEUROPATHY
WHAT IS INVOLVEDWHAT IS INVOLVED
LOCATIONLOCATION
Ulnar Nerve
Most frequently at the Elbow from leaning on it or trauma
COMMON SYMPTOMSCOMMON SYMPTOMS
Weak hand, dropping objects, difficulty turning keys, ignition, doorknobs
Numbness/tingling fourth, fifth fingers
Wasting of the interosseii muscles
Occasional elbow soreness
Symptoms not related to night/daytime
Frequently on both sides
SHOULDER / ARM / HAND PROBLEMS SHOULDER / ARM / HAND PROBLEMS /CARPALTUNNEL SYNDROME/CARPALTUNNEL SYNDROME
WHAT IS INVOLVEDWHAT IS INVOLVED
LOCATIONLOCATION
Median Nerve at the wrist
The Carpal Tunnel, at the wrist
COMMON SYMPTOMSCOMMON SYMPTOMS
Worse in the dominant hand
Dropping objects
Numbness tingling, hand/wrist ----> Thumb, Index and/or Middle finger
May radiate up the arm, occasionally to the shoulder
Symptoms primarily at night. Patient wakes up and shake their hands to obtain relief
Frequently bilateral, although may only be symptomatic on one side
VEPVEP
BAEPBAEP
SSEPSSEP
VISUAL
EVOKED
POTANTIAL
:- To check the electrical activity of optic (eyes) nerve.
Amplifier parameters
Channels Sensitivity Scaling for analysis
fo fu 50 Hz notch Rctf. Ext.Input
Auto-matic offset
1 20 µV/div 2 µV/div 100 Hz 0,5 Hz x x
Aquisition-parameters
Monitor time
Analysis time
Trigger-mode
Averagermode
Sweeps (no. of passes)
Artefacttreshold
ArtefactDetection
20 ms/div
50 ms/div Internal Standard 50 95 ---
Stimulation-parameters
Stim. Ferquency Stim. Type Stim. Field Size Pattern
Stim. Mode
Contrast Traces
1 Hz Pattern Full Standard Check Invert light 3
BRAIN
AUDITORY
EVOKED
POTENTIAL
:- To check the electrical activity of
hearing nerves.
Amplifier parameters
Channels Sensitivity Scaling for analysis
fo fu 50 Hz notch
Rctf. Ext.Input
Auto-matic offset
1 10 µV/div 200 nV/div 3 kHz 100 Hz x
Aquisition-parameters
Monitor time
Analysis time
Trigger-mode
Averagermode
Sweeps (no. of passes)
Artefacttreshold
ArtefactDetection
20 ms/div 1 ms/div Internal Standard 2000 15 500 µs
Stimulation-parameters
Stim. Ferquenc
y
Stim. Type
Stim. Field Polarity Volume stimulus Volume noise Contrast
15 Hz Click 200 µs alternated 70 dB relativ 40 dB, relativ 4
SOMATO
SENSORY
EVOKED
POTENTIAL
Somatosensory Evoked Potential (SSEP) is a test showing the electrical signals of sensation going from the body to the brain. The signals show whether the nerves that connect to the spinal cord are able to send and receive sensory information like pain, temperature, and touch. When ordering electrical tests to diagnose spine problems, SSEP is combined with an electromyogram (EMG), a test of how well the nerve roots leaving the spine are working.
An SSEP indicates whether the spinal cord or nerves are being pinched. It is helpful in determining how much the nerve is being damaged. SSEP is used to double check whether the sensory part of the nerve is working correctly.
Amplifier parameters
Channels Sensitivity Scaling for analysis
fo fu 50 Hz notch Rctf. Ext.Input
Auto-matic offset
SEP N. tibialis 2 10 µV/div 2 µV/div 1 kHz 2 Hz x x
SEP N. medianus 1 10 µV/div 2 µV/div 1 kHz 2 Hz
Aquisition-parameters
Monitor time
Analysis time Trigger-mode
Averagermode
Sweeps (no. of passes)
ArtefactDetection
Aquisitionparameters
SEP N. tibialis 20 ms/div 10 ms/div Internal Standard 400 --- ---
SEP N. medianus 20 ms/div 10 ms/div Internal Standard 200
Stimulation-parameters
Stim. Ferquency
Stim. Mode Duration Stimulation current step
Traces
SEP N. tibialis 3 Hz Single puls 200 µs Automatic 4
SEP N. medianus 3 Hz Single puls 200 µs Automatic 2
REPETITIVE
NERVE
STIMULATION
RNS TEST IS USED FOR RNS TEST IS USED FOR MYASTHENIA GRAVIS: MYASTHENIA GRAVIS:
DIAGNOSTIC TESTSDIAGNOSTIC TESTS
Decremental response to RNS in Myasthenia Gravis
MYASTHENIA GRAVISMYASTHENIA GRAVIS
Tensilon test: Before (left); After (right)
Cogan
Repetitive Nerve Stimulation
NERVE CONDUCTION QUICK SET-UPS | BLINK / FACIAL
H-Reflex (Soleus) H-Reflex Potentials
Transcranial Doppler (TCD) ultrasound is a non-invasive method to estimate the blood flow velocities in the large intracranial vessels of the circle of Willis. Using established TCD techniques, sections of the internal carotid artery (ICA), middle cerebral artery (MCA), anterior carotid artery (ACA), posterior cerebellar artery (PCA) and the basilar and periorbital arteries can be examined. TCD typically uses a 2 MHz pulse ultrasound which produces a velocity spectrum throughout the cardiac cycle.
MCA:- Middle Cerebral ArteryMCA:- Middle Cerebral Artery
ACA:- Anterior Cerebral ArteryACA:- Anterior Cerebral Artery
PCA:- Posterior Cerebral ArteryPCA:- Posterior Cerebral Artery
Vertebral Artery Vertebral Artery
Basilar Artery Basilar Artery
Vertebral ArteryVertebral Artery Basilar ArteryBasilar Artery