STEREOTACTIC NEUROSURGERY OR STEREOTAXY
It is a surgical intervention to precisely locate small targets deep inside the brain & to perform actions such as ablation (radio frequency or RF), biopsy, injections, stimulation implantation, radiosurgery, etc,. Done by using an external 3D frame of reference usually based on the Cartesian co-ordinate system.
Many of the above problems are as a result of ‘misbehaving/misfiring’ electrical brain circuits! Neuro modulation attempts to correct this.
What is Neuromodulation?’
The INS (the International Neuromodulation Society) defines neuromodulation as a field of science, medicine, and bioengineering that encompasses implantable and non-implantable technologies, electrical or chemical, for the purpose of improving quality of life and functioning of humans.
Neuromodulation is “technology impacting on the neural interface.” Neuromodulation devices and treatments are life changing. They affect every area of the body and treat a wide range of diseases or symptoms from headaches to tremors to spasticity to spinal cord damage to urinary incontinence. With such a broad therapeutic scope, and significant ongoing improvements in biotechnology, it is not surprising that neuromodulation is poised as a major therapy option in the next decade.
WHAT IS A MOVEMENT DISORDER(MD)?
Movement Disorders are clinically, pathologically & genetically a heterogenous group of diseases characterized by impairment of PLANNING, CONTROL & EXECUTION of movements.
There are two types:
1. HYPOKINETIC – characterized by Akinesia (paucity of movements), Bradykinesia (slowness of ovements) and Rigidity (involuntary increase in muscle tone),
cogwheel type (if associated with tremors). Eg: Parkinson’s Disease or Parkinsonism
2. HYPERKINETIC – are disorders in which there is EXCESSIVE MOVEMENTS – either spontaneous, in response to volitional movement or to another stimulus. Most often involuntary.
Eg: Essential tremors , Dystonia, Chorea, Ballism, Athetosis
Tremors can be either rest or action tremors.
Types of Tremors that benefit from surgery include:
Tremor- dominant Parkinson’s Disease Essential Tremors
Post MS (Multiple Sclerosis) Tremor Post-stroke Tremor
Post-head injury Tremor Dystonic Tremor
Dystonia is a movement disorder in which a person’s muscles contract uncontrollably. The contraction causes the affected body part to twist involuntarily, resulting in repetitive movements or abnormal postures. Dystonia can affect one muscle, a muscle group, or the entire body.
Types of DYSTONIA that may benefit from surgery include: (both in children & adults)
Spasmodic torticollis Generalized Dystonia Axial/ segmental Dystonia Focal-hand Dystonia- task-specificity – like writers cramp, occupational dystonia (ex: barber’s dystonia, musicians dystonia, etc.)
PARKINSON’S DISEASE (PD)
Parkinson’s Disease (PD) is the most common neurodegenerative cause of Parkinsonism, a clinical syndrome characterized by lesions in the basal ganglia, predominantly in the substantia nigra. PD makes up approximately 80% of cases of Parkinsonism.
Levodopa is the mainstay in the medical management. However, the progression of the disease, combined with prolonged Levodopa use can result in some disabling motor symptoms such as:
ON-OFF PHENOMENON FREEZING PEAK DOSE DYSKINESIAS
Two types of Parkinson’s Disease: 1. Tremor predominant- unilateral and slow to progress 2. Rigidity-bradykinesia predominant- early bilaterality & relatively rapid progress.
PD has both MOTOR SYMPTOMS & NON-MOTOR SYMPTOMS
Every Parkinsonism patient needs a detailed clinical evaluation by a specialized Movement Disorder neurologist and have his UPDRS assessments done. Every patient will need a Levodopa challenge test before qualifying them for surgical intervention
Every patient with Movement Disorders & Spasticity will need to be evaluated in detail by a qualified Movement Disorders Neurologist who will establish the right diagnosis, assess the severity of symptoms (by standardised scales) and decide on the need, benefit and timing of surgery.