CANMAT Guidelines: Depression Part 3 (neurostimulation etc) Flashcards
(206 cards)
name the first line neurostimulation treatment recommended by the guidelines for MDD?
under what conditions is this recommended?
tTMS
(if FAILED at least one antidepressant)
what level evidence is there for rTMS for MDD in the acute and maintenance phases
level 1 for acute and level 3 for maintenance
(has level 1 evidence for safety and tolerability)
what is the second line neurostimulation treatment recommended by the guidelines for MDD
ECT (it is first line in some situations)
what level evidence is there for ECT for MDD
level 1 for acute and maintenance, and for safety and tolerability
WE HAVE GOOD EVIDENCE ECT WORKS AND IS SAFE AND TOLERABLE
list two third line neurostimulation treatments for MDD
tDCS
VNS
list two investigational neurostimulation treatments for MDD
DBS
MST
what is tDCS
transcranial direct current stimulation
a form of brain stimulation that delivers a CONTINUOUS, LOW AMPLITUDE electrical current to a specified cortical region using SCALP electrodes
list some advantages of tDCS
ease of use
low cost
portability
potential for home based use
ability for combination with other treatments
low potential for adverse effects
what is the effect of ANODAL stimulation in tDCS
anodal stimulation over the cortex INCREASES cortical excitability through DEpolarization of neuronal membrane potential
what is the effect of CATHODAL stimulation in tDCS
cathodal stimulation DECREASES cortical excitability through HYPERpolarization of the neuronal membrane potential
what is the hypothesized mediator of the effects of tDCS
NMDA receptor-dependent mechanisms
are there clear parameters for the optimal delivery of tDCS
no cohesive summary
exact frequency and duration of stimulation have not been established
how is tDCS generally delivered (i.e placement of electrodes etc)
anodal stimulation over the left DLPFC
+
cathode used as a ground over a noncortical region
OR
anodal stimulation over the left DLPFC and cathodal stimulation over the right DLPFC
what is an often used parameter for frequency and intensity for tDCS treatment (to observe and antidepressant effect)
seems that minimum stimulation with 2 milliamperes (mA) for at least 30 min per day for 2 weeks is necessary to observe an antidepressant effect
is tDCS monotherapy or combo therapy with SSRI better
combo
is tDCS well tolerated
yes generally
what are the most common side effects of tDCS
regional effects at skin–> redness, itching, burning, heat, tingling
low rates observed of headaches, blurred vision, ear ringing, fatigue, nausea, mild euphoria, reduced concentration, disorientation, insomnia, anxiety
is there a risk of hypomania or mania with tDCS
yes–> found in study where tDCS was combined with sertraline though
what is rTMS
uses powerful (1-2.5 Tesla), focused MAGNETIC FIELD PULSES to induce electrical currents in neural tissue noninvasively via an inductor COIL placed against the SCALP
is anesthesia required for rTMS
no
do we have a clear understanding of the mechanism by which rTMS has antidepressant effects
no–> mechanisms proposed at both cell-molecular and network levels
what is a standard protocol for rTMS
once daily, 5 days per week
(there are some slower and faster schedules being investigated)
maximal effects found at about 26-28 sessions
stimulation delivered in 2-10 second trains at 10-60 sec intervals in 15-45 min sessions
how is stimulus intensity determined for rTMS? what is the most common stimulus intensity prarameter for rTMS?
stimulus intensity based on individually determined resting motor threshold (RMT–> minimum intensity to elicit muscle twitches at relaxed upper and lower extremities)
most common intensity is 110%-120% RMT
what are the two first line rTMS stimulation protocols
high frequency rTMS to left DLPFC
low frequency rTMS to right DLPFC
*there are other protocols as well but i will never remember them