In a famous incident in 1848, Mr Phineas Gage, a 25-year-old railroad worker, sustained severe damage to his frontal lobes when a metal tamping rod was blasted through his head after a freak accident...

Gage`s accidental frontal lobotomy laid some of the groundwork for the surgical procedure of frontal (prefrontal) lobotomy...

This operation became popular in the mid-twentieth century; it was done extensively over a period of years not only for psychosis but also for neurosis and depression... recommended for “difficult children”.

The Frontal Lobes:An approach

Mark KeezerR4 NeurologyDec 1, 2010

Multiple Divisions of the Frontal Lobe

• Motor cortex• Premotor & Supplementary Motor cortex

• Apraxia• Frontal Eye Fields• Broca’s Area.

The Remainder

• Prefrontal Cortex– Orbitofrontal Cortex (OFC)– Medial Prefrontal Cortex (MPC)– Dorsolateral Prefrontal Cortex (DLPFC).

To begin with...

Sustained Attention• Digit span (7 forward, 4 backward)• Serial 7’s• WORLD• Months/days of the week backwards.

Orbitofrontal Cortex

• Disorder of Social Conduct (right hemisphere)– Dis-inhibited, impulsive behaviour– Poor hygiene, promiscuity, spending money– Poor judgement and insight– Emotional lability– Euphoria– Witzelsucht (transl: joke addiction)

– Facetiousness, inappropriate levity and senseless joking.

Orbitofrontal Cortex

• On examination– Anosmia.

Working Memory (perhaps more OFC)

• Verbal & spatial working memory.

Medial Prefrontal Cortex (including Cingulate Cortex)

• Akinetic/apathetic/abulic syndrome– Paucity of spontaneous movement and gesture– Sparse verbal output

• Repetition may be preserved• Urinary (& fecal) incontinence

– Micturition centre.

Medial Prefrontal Cortex

• On exam– Lower extremity weakness.

Frontal Gait Disorder (perhaps more MPC)

• “...the disorder represents a loss of integration, at the cortical and basal ganglionic levels, of the essential instinctual elements of stance and locomotion that are acquired in infancy...”

• Short-stride, shuffling, hesitant steps

• Magnetic gait– Ignition apraxia

• Turning by small steps with one foot, the other planted as a pivot

• Retropulsion.

Dorsolateral Prefrontal Cortex

• Dysexecutive syndrome– Ability to plan, monitor, and carry out an

activity to achieve a goal

– Poor judgement

– Indifference (almost “la belle…”).

Dorsolateral Prefrontal Cortex

• On exam– Abstract thought (orange & apple, chair & table, watch

& ruler, tree & ant)

– Judgment

– “You arrive in Vancouver, you’ve lost your friend’s phone number and they are not listed in the phone book. How do you find them?”

– Executive function

– Perseveration due to difficulty abandoning the initial pattern of responses.

Executive Function• Go-no-go (inhibitory control; 1=2, 2=0)

• Conflicting instructions (sensitivity to interference; 1=2, 2=1)

• Louria sequences (fist, edge, palm)

• Lexical fluency (>11 words in 1 minute = normal)

• Trails

• Clock drawing

• Stroop test

• String of M’s and N’s

• Applause sign.

GLASS

TLCC

Frontal Release Signs (perhaps more DLPFC)

• Palmar grasp– Don’t warn them, just lay their hands down and touch then and see if they

hold your hands spontaneously

• Glabellar tap (Meyerson’s sign)

• Palmomental reflex (the only with localization value)

• Snout reflex

• Rooting reflex

• Utilization behaviour

• Echolalia & Echopraxia.

A popular procedure was the “ice-pick” lobotomy in which an ice pick was inserted above the eye and pounded through the orbital roof with a mallet, then swept to and fro...

The primary proponent of this technique used a gold-plated ice pick and kept speed records for the procedure. A lobotomy was once done on an eccentric actress who had no mental illness... The procedure has been abandoned.