AANS YouTube Channel

The American Association of Neurosurgeons have put a great YouTube Channel that has educational videos including power points, surgical videos, and lectures. I've learned a lot from it. It is definitely worth checking out if you are interested in neurosurgery!



My first couple days in Neurosurgery have been awesome. I have spent 90% of the time scrubbing into cases so I have had the chance to participate is some cool surgeries. Next week I will spend some time on the floors as well as in the OR which I am looking forward to.

Some of the procedures that I've been in on this week:
1. C1-C3 Fusion for an occipital fx
2. Carpal Tunnel release
3. Lateral Approach L3-L5 fusion for scoliosis
4. Burr Hole and EVD placement
5. Cranioplasty

The Cranioplasty was one of my favorite so far, so that is what I'll write about today.

1. Cosmetic restoration of external skull symmetry
2. Sx relief secondary to craniotomy
3. Protection from trauma in an area void of skull bone

Material Options (some):
1. Methylmethacrylate
2. Titanium mesh
3. Split thickness calvaria
*It is recommended that foreign materials be perforated to prevent fluid collections underneath


Basic Suturing Technique

There are a ton of suturing tutorial videos online, but I often find that it is tough to see exactly what they are doing in the videos. SIM SUTURE is a company that makes an at-home practice kit so they came up with a 7 part suturing tutorial that has great lighting, instructions, and visuals. Happy sewing!


My Elective in Neurosurgery

So I am about to embark on my elective rotation - Neurosurgery. I can't wait. I am lucky enough to be doing my elective at a Level 1 Trauma Center in a Neurosurg Dept that does not have residents. This means that PAs get to DO a ton (first assist on surgeries, do most of the on-floor procedures, etc). In honor of my elective I wanted to post something with a neurosurgical flair...

Neuro Trauma - Notes on Initial Assessment
  • Standard ABC
    • -Blood pressure
    • -Oxygenation
  • GCS
  • Pupil exam
  • Motor Strength
*Pay special attention to hypOtension and hypoxia for the following reasons:
  • HypOtension = doubles mortality
  • Hypoxia = increases mortality
  • Both = 3x increase in mortality


*HypOtension is rarely attributable to head injury (I will not go into the few exceptions to this.)

Neurogenic Shock:
  • Occurs in Spinal cord injuries above T1
  • Due to interruption of sympathetics
o    Loss of vascular tone below the level of injury – incidence increases with injuries above T6
  •       Parasympathetics are unopposed

o    Bradycardia
o    Venous pooling
o    Lower systemic vascular resistance 

Initial Survey in Neurotrauma:
  • Look for injuries to head, spine, eyes, TMs, and CSF leaks
  •        Look for basilar skull fx (NEVER insert NG tube if basilar fx is suspected!)

o    Raccoon eyes
o    Battle sign
o    CSF rhinorrhea/otorrhea
o    Pts describe salty or metallic taste
o    Collect fluid: quant glucose/beta2 transferrin (Ring sign at bedside)
  •        Look for facial fx

o    Lefort fx
o    Orital rim fx
  •       Periorital edema
  •       Cranio-cervical auscultation

o    Auscultate over the globe of the eye: bruits my indicate traumatic C-C fistula
o    Auscultate over the carotid a.
GCS: GCS of 8 or less = coma


Source: The Society of Neurological Surgeons - "Neurological and Neurotrauma Assessment" 
Photo: http://www.thebarrow.org/Neurological_Services/Neurotrauma/index.htm


General Pituitary Gland Pathology 101

Location: centrally in the sphenoid bone of the skull within the sella turcica

Adenohypophysis: Another name for the anterior pituitary. Develops from Rathke's pouch (in the mouth)

Anterior Pituitary Cells:
-Somatotrophs - produce GH
-Lactotrophs - produce prolactin
-Corticotrophs - produce adrenocorticotrophic hormone (ACTH) and melanocytic-stimulating hormone (MSH)
-Thyrotrophs - produce TSH
 -Gonadotrophs - produce FSH and LH

Neurohypophysis: Another name for the posterior pituitary. Develops from the brain.

Posterior Pituitary Cells
-produce ADH and oxytocin


Causes of Hearing Loss

Ambulatory Topic #2: Causes of Hearing Loss

At my present clinic, my attending does the annual physical exam for the state-employed divers. Many of them have exostoses, which are bony outgrowth of the external auditory canal related to repetitive exposures to cold water. They are common in divers and swimmers. This led us into a conversation about hearing loss and thus my topic of the day.

There are 2 types of hearing loss: Conductive vs Sensorineural

Conductive = caused by lesion in external or middle ear
Sensorineural = lesions in cochlea or CN VIII

1.     External canal
a.     WAX! (Cerumen impaction)
b.     Otitis externa (TIP: Don’t forget to palpate external ear before introducing otoscope!)
c.      Exostoses

2.     TM performation
a.     Trauma
b.     Secondary to middle ear infection

3.     Middle ear
a.     Middle ear effusion (Otitis media, allergic rhinitis)
b.     Otosclerosis (bony fusion between stapes and ova = immobilization)
c.      Neoplasm
d.     Congenital malformation

1.     Old Age (Presbycusis)
a.     Degeneration of sensory cells

2.     Too many concerts (Noise-induced hearing loss)
a.     >85 dB for prolonged time
b.     Damaged hair cells

3.     Infection
a.     Viral or bacterial

4.     Drug-induced hearing loss
a.     Aminoglycosides
b.     Cisplatin
c.      Furosemide
d.     Aspirin can cause tinnitus (usually reversible)

5.     Inner ear injury
a.     Skull fx

6.     Meniere’s Dz
a.     Fluctuating, unilateral hearing loss
b.     Ear feels “full”
c.      Vertigo
7.     CNS cause
a.     Acoustic neuroma
b.     Meningitis
c.      Neuritis of auditory nerve

8.     Congenital
a.     TORCH infections

Tips on Hearing Tests:
Rinne Test (Abnl)
Bone conduction (BC) > Air conduction (AC)
Weber Test
Sound lateralizes to AFFECTED side*

Rinne Test (Nl)
Weber Test
Sound lateralizes to UNAFFECTED side

*This means that the tuning fork is heard louder in the ear with the conductive hearing loss.
I remember it as the Rinne test is Abnormal and sound lateralizes to the Affected side. Both start with “A”.

Source: Step Up to Medicine 2nd Ed.

Atypical vs. Typical CAP - Clinical Signs/Sx

Definition of CAP: Community Acquired Pneumonia is acquired in the community or within the first 72hrs of hospitalization

S. pneumo (most common)
H. Flu
Staph aureus

Clinical Symptoms:
Quick onset with fever/chills
Pleuritic chest pain
Productive (thick) cough

late inspiration crackles

Lobar consolidation

Doxycycline, Azithromycin, Clarithromycin, Flouroquinolones

Mycoplasma pneumoniae (most common)
Chlamydia pneumoniae
Chlamydia psittaci 
Coxiella burnetii

Clinical Symptoms:
Slow onset
HA, sore throat, fatigue, myalgias
Dry cough

normal pulse with high fever

Diffuse infiltrates
No/minimum consolidation

start empiric tx with:
 erythromycin (for Mycoplasma pneumoniae and Legionella)
tetracycline (for Chlamydia pneumoniae)

Pic: http://emedicalppt.blogspot.com/2011/02/community-acquired-pneumonia-cap.html
Source: Step Up to Medicine 2nd Ed Agabegi and Agabegi


Paracentesis Video

I am in my Ambulatory clinical rotation and I was able to do 2 paracentesis procedures in one day. One was therapeutic (drained 13L) and one was diagnostic. It was awesome! I love doing procedures.


Ambulatory Topic #3: QT Intervals

Ambulatory Topic #3: QT Intervals

Normal QT Interval:
less than 1/2 of the R-R interval (approx <0.42s)

Causes of Prolonged QT:
2-Electrodisturbances (hypOCa+ and hypOK+)
5-CNS lesion

How to get the corrected QT interval (QTc):

What is it "correcting" for? The heart rate. The length of the QT interval is obviously dependent on the rate the heart is pumping so the QTc adjusts for this.

Pic: http://www.mayoclinic.com/health/medical/IM02677
Pic: http://heart.bmj.com/content/93/9/1051.abstract