BRAIN WITH PING PONG BALLS

Jessie Hill, a six-year-old girl, had half of her brain removed surgically, by Dr. Ben Carson at John's Hopkins Children's Centre in Baltimore. 

Jessie was a normal child until she was 6 years old. That is when she began having seizures.

Her parents learned she had a disease on the right side of her brain called Rasmussen’s Encephalitis. If left untreated, it would spread to the left side of her brain and eventually kill her.

Dr. Ben Carson recommended hemispherectomy surgery and removed the diseased right half of Jessie's brain in a surgery that lasted hours long. The surgery was followed by rehabilitation that helped Jessie regain all the lost functions. 

In an interview, Jessie recalls, “I remember just being. I wanted to go home. I didn’t really understand why I was there like — I just didn’t want to be any part of therapy or anything because it was painful.”

During her treatment in Baltimore, her parents formed the Hemispherectomy Foundation. 

INTERESTING TO KNOW:

When surgeons were first developing the procedure, they tried to fill the empty cavity on one side of the skull, in one case using sterile ping-pong balls, but they later realized that the brain’s own cerebrospinal fluid eventually fills the space.

 RASMUSSEN'S ENCEPHALITIS

Rasmussen's encephalitis is a rare, progressive, chronic encephalitis that primarily affects children below 10 years of age. It affects only one hemisphere of the brain.

CAUSES:

The exact causes of the disease are unknown. 

However, some theories believe in the autoimmune mechanism, antibodies against gluR3 subunit of the alpha-amino-3-hydroxyl-5 methyl-4-isoxazole propionic acid (AMP receptors) in a few patients and according to a review of the involved tissue under the microscope.

Whereas, some theories believe that RE may be triggered by an unidentified infection, such as influenza, measles, or CMV.

SYMPTOMS:

1. Seizures- which may be simple partial, complex partial, or generalized clonic-tonic convulsions. Epilepsia partialis continua are observed in almost 50% of the cases. 

2. Hemiparesis - Weakening of the contralateral side of the body is a significant feature. 

3. Cognitive Impairment- These depend on whether the right or the left hemisphere is affected. The patient may suffer aphasia, learning impairment, speech disability, dysarthria, and other sensory deficits.

 

DIAGNOSIS:

Diagnosis is mainly based upon the radiological examination, which consists of EEG (Electroencephalography) and Serial Magnetic Resonance Imaging. The EEG shows the pattern which is characteristic of epilepsy. Serial MRI shows atrophy and scarring of the affected brain. 

TREATMENT:

The treatment options include Anti-convulsive therapy, Immunomodulatory Therapy, and hemispherectomy. 

Anticonvulsive therapy can not fully treat the seizures, it can only limit the frequency of the seizures. Immunomodulatory therapy includes steroids, Intravenous Ig immunoglobulin, tacrolimus, azathioprine, etc. These drugs can also only slow down the illness and not cure it. 

Hemispherectomy is a modern surgical treatment option available that provides a cure for seizures, but it comes with its own costs, the various complications, which may include, hemianopia, hemiplegia, swallowing difficulties, speech loss, etc. 

HEMISPHERECTOMY

A hemispherectomy is a radical surgical procedure where the diseased half of the brain is completely removed, partially removed, and fully disconnected or just disconnected from the normal hemisphere. 

There are 2 main types of hemispherectomies: anatomic and functional. 

• An anatomic hemispherectomy involves physically removing the diseased hemisphere of the brain including the frontal, parietal, temporal, and occipital lobes.  
• A functional hemispherectomy is an evolution of the anatomic hemispherectomy in which less brain is removed, however, the diseased hemisphere of the brain is completely disconnected from the normal hemisphere of the brain. 

INDICATIONS:

Hemispherectomy is indicated in patients with medically intractable epilepsy due to unilateral  hemispheric    lesions.  Among them are included congenital  (extensive,  plurilobar cortical  dysplasia, hemimegalencephaly,  congenital  extensive  porencephaly,  and  SturgeWeber  syndrome),  and  perinatal  disorders  (middle  cerebral  artery extensive  infarcts,  perinatal  occlusion  of  the  Sylvian  aqueduct, Rasmussen  encephalitis,  West  syndrome,  and  Lennox-Gastaut syndrome).

ANAESTHESIA:

The  procedure  is always  performed  under  general  endotracheal  anesthesia  and  invasive cardiopulmonary  monitoring  (central  venous  line,  intra-arterial  line, transurethral  catheter  insertion).  Warm  air-blanket  and  intravenous fluids  are  essential  for  preventing  perioperative  hypothermia. A  loading  dose  of  steroids (dexamethasone)  may  be  given  intravenously  in  the  morning  of  the surgery.  Antibiotics,  a  gastro-protective  agent,  and  anti-epileptic treatment are also indicated.

THE PROCEDURE:

The patient is positioned supine with a small shoulder bump and the head turned to the contralateral side. 

Neuronavigation is very useful for confirming anatomical landmarks and ensuring that the midline is not breached during corpus callosotomy.

A  skin  incision  should  permit  sufficient  exposure  of  the  working window. It  is  of  importance  to minimize  bleeding  with  the  use  of  Raney  clips  and  bipolar  cautery, especially  in  children.  The  skin-flap  is  elevated  and  reflected anteriorly.  The  underlying  temporalis  fascia  is  reflected  anteriorly.

The underlying  dura  is  detached  from  the  bone  with  a  #3  Penfield dissector.  The  adjacent  burr  holes  are  connected  with  a  craniotome and  the  bone  flap  is  carefully  removed. 

The dura is opened anteriorly, inferiorly, and posteriorly. Dural  incision  bleeding is  controlled  with  hemostatic  clips.  The  dural  flaps,  based  toward  the midline,  are  reflected.

Operative setup and left-sided osteoplastic craniotomy. A and B: The patient is positioned supine with the head turned to the contralateral side. The temporal lobe should be at the apex of the operative field and parallel to the floor. In patients younger than 2 years, the Infinity Mayfield head holder is used to immobilize the skull. Optical neuronavigation is used, and the monitor is placed at the head of the bed. Ant = anterior; post = posterior. C: The skin flap is reflected above the superficial fascia until the frontal fat pad appears. A subfascial dissection through the deep temporalis fascia is performed and elevated with the skin flap anteriorly to preserve frontal branches of the facial nerve. D and E: A large frontotemporal craniotomy is performed while preserving the overlying temporalis muscle attachments. F: The dura is opened, and the dural edges are tacked up to reduce runoff into the surgical cavity and prevent epidural collections. The locations of the frontal lobe (F), temporal lobe (T), sylvian fissure (white dotted line), and midline (black dotted line) are shown.

• Anatomical  hemispherectomy  (AH)  is  performed  under  the surgical  microscope  and  achieved  in  three  phases.  Initially,  the  Sylvian fissure  is  opened. 
• In  the  second  step,  the  corpus  callosum  is  properly  identified  and divided  through  an  interhemispheric  approach. 
• Finally,  the  fronto-basal  white  matter  is  divided  through  the anterior  part  of  the  lateral  ventricle.  The  temporal  stem  is  dissected and  the  ipsilateral  anterior  choroid  and  posterior  communicating arteries  are  identified.  The  latter  is  clipped  and  divided  at  its  P3 segment.  The  amygdala  and  the  hippocampus  are  removed  employing sub-pial  dissection  with  special  care  on  the  preservation  of  the occulomotor  nerve.

• 
  Lateral disconnection. A: To disconnect the fibers forming the internal capsule and corona radiata, a cortisectomy is performed in the middle frontal gyrus into the frontal lateral horn of the lateral ventricle. The locations of the frontal lobe (F), temporal lobe (T), sylvian fissure (white dotted line), and midline (black dotted line) are shown. B: The cortisectomy is extended posteriorly to the supramarginal gyrus following the course of the lateral ventricle into the atrium and turns inferiorly toward the temporal horn. C: Coronal MR image showing the locations of the frontal (red dotted line) and temporal (white dotted line) cortisectomies. D: To facilitate surgical access, the frontal (white arrow) and temporal (black arrow) opercula are resected to expose the insula. E: The insular cortex is resected in a plane, which preserves the basal ganglia structures (asterisk). F: Axial MR image showing the location of the insular resection (red dotted line). G: Cadaveric specimen showing cortisectomy and exposure of the lateral ventricle anteriorly and posteriorly. The dissector is passed through the foramen of Monro. H: Cadaveric specimen showing removal of the opercula and insula.
  
  

Functional  hemispherectomy  (FH)  is  a  four-step  process. 

• The  temporal  lobe  is  removed  with  two  cortical  incisions,  one  on  the superior  temporal  gyrus,  running  in  parallel  to  the  Sylvian  fissure,  and a second one placed on the dorsal temporal lobe, down to the temporal base,  perpendicular  to  the  first  one. 
• The  second  step  involves  removal  of  the  suprasylvian  cortex  by  two parallel  incisions  perpendicular  to  the  sylvian  fissure,  and  providing access  into  the  ipsilateral  lateral  ventricle. 
• Completion  of  the  transventricular  parasagittal  callosotomy  is  the main  task  of  the  third  step.  
• The  remaining  anterior  and  posterior callosal  fiber  tracts  are  disconnected  from  the  ependymal  surface toward  the  cingulate  gyrus. Lastly,  anterior  and  posterior  disconnections  of  the  frontal  and parieto-occipital  lobes  take  place.

• 
  Mesial temporal resection. A: The temporal horn of the left lateral ventricle is opened to reveal the hippocampus (asterisk) and mesial structures. B: The anterior temporal lobe is resected, paying careful attention to the medial pial plane. When resection is complete, the oculomotor nerve is visualized on the other side of the pia (green arrow). C: Coronal MR image showing the temporal resection (red dotted line) and the relative position of the oculomotor nerve (green dot). D: Cadaveric specimen demonstrating the operative anatomy in panel A. The temporal horn is retracted to show the hippocampus (asterisk). The inferior choroidal point (black arrow) and the MCA bifurcation (limen insulae; yellow arrow) are connected and represent the medial extent of the amygdalectomy (red dotted line). E: The cadaveric specimen is reoriented to show the anatomical position of the hippocampus (asterisk), inferior choroidal point (black arrow), and MCA bifurcation (yellow arrow). TF = temporal floor; TP = temporal pole.

• 
  Corpus callosotomy and completion of disconnections. A and B: Sagittal (A) and coronal (B) MR images showing the corpus callosotomy. The septum pellucidum is identified in the lateral ventricles, and the callosotomy is commenced millimeters lateral to the midline (red dotted lines). Anatomically, pericallosal branches of the ACA and the falx serve as landmarks (white arrow). The callosotomy is taken posteriorly through the body to the splenium until the atrium and the tentorial edge are reached (green dotted arrow). Anteriorly, the dissection follows the ACAs past the genu of the corpus callosum and courses inferiorly and posteriorly through the rostrum (yellow dotted arrow). C and D: Intraoperative views of the transventricular callostomy. The pericallosal ACA is outlined (white dotted line). CC = corpus callosum; S = midline septum. E and F: Anteriorly, the dissection through the rostrum of the corpus callosum is taken medially to the interhemispheric fissure and inferiorly to the anterior skull base. The frontobasal disconnection is completed, and the A1–2 junction serves as the posterior limit of the dissection (tip of the Penfield dissector). The dotted lines and white arrow in panel E denote the region of interest and direction of view, respectively, in panel F. G: Cadaveric specimen showing the transventricular corpus callostomy and ACA. H: Completion of the frontobasal (white arrow) and the parietooccipital (black arrow) disconnections. The basal ganglia and thalamus have been removed to aid anatomical visualization.

CLOSURE:

After  completing  the  resective  or  disconnective  part  of  the procedure,  the  surgical  cavity  is  thoroughly  irrigated  in  order  to remove  small  blood  clots  and  debris. The  bone  flap  is  secured  back  in  its  position  by  mini-plates and  screws  or  by  silk  sutures.  The  surgical  wound  is  closed  in anatomical  layers. 

COMPLICATIONS:

Occasionally, some complications may occur including the need for a blood transfusion, aseptic meningitis, postoperative fevers and infection.  Hydrocephalus (excess brain and spinal fluid in the brain) is condition that can occur either immediately after surgery or years later.  This is very effectively treated through placement of a shunt.

REFERENCES:

1. Brotis, A. G. (2015). Hemispherectomy: Indications, Surgical Techniques, Complications, and Outcome. Journal of Neurology & Neurophysiology, 06(04). https://doi.org/10.4172/2155-9562.1000300
2. A case of Rasmussen’s Encephalitis | Pediatrics. (2021, October 23). [Video]. YouTube. https://www.youtube.com/watch?v=U2KXmakNh3w&t=368s
3. E. (2016, August 18). Six Surgical Miracles. America College of Surgeons - Ohio. https://ohiofacs.org/six-surgical-miracles/
4. Hemispherectomy - Epilepsy Treatment - UCLA Health Pediatric Neurosurgery, Los Angeles, CA. (n.d.). UCLA Health. https://www.uclahealth.org/mattel/pediatric-neurosurgery/hemispherectomy#:%7E:text=A%20hemispherectomy%20is%20a%20radical,seizures%20in%20carefully%20selected%20patients.
5. Koch, D. (2021, May 21). A Medical Miracle: 12 Years After Half Of Her Brain Was Removed, Jessie Hall Shares How It Inspired Her To Help Others. Baltimore.Cbslocal.Com. https://baltimore.cbslocal.com/2021/05/20/jessie-hall-medical-miracle-half-brain-removed-johns-hopkins/
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8. Symptoms of rasmussen’s encephalitis. (n.d.). [Photograph]. https://www.verywellhealth.com/thmb/q_hEeC7xUomNq6NjgNo6uGG8FuQ=/614x0/filters:no_upscale():max_bytes(150000):strip_icc():format(webp)/rasmussen-s-syndrome-and-rasmussen-s-encephalitis-4138156-01-164e4ba1640a4ae68f17d515b6648cf6.png
9. Transparent high-resolution EEG array. (n.d.). [Photograph]. https://www.drugtargetreview.com/wp-content/uploads/brain-connectivity-e1536311594713.jpg
10. Young, C. C., Williams, J. R., Feroze, A. H., McGrath, M., Ravanpay, A. C., Ellenbogen, R. G., Ojemann, J. G., & Hauptman, J. S. (2020). Pediatric functional hemispherectomy: operative techniques and complication avoidance. Neurosurgical Focus, 48(4), E9. https://doi.org/10.3171/2020.1.focus19889