Summary Chapter 7 + lecture
notes
Vascular Dementa
Vascular Dementa VaDD s the second mos t prevalen t sub type of dementaa n persons aged 85 or
older, VaD s more common than ADa More men appear to be afec ted by VaD than womena
R sk fac tors: hypo- and hyper tens on, card ovascular d sease, d abe tes, smok ng, age, low educaton
level eaga no t challeng ng yourselfD, lacunar s trokes and wh te mater les onsa
Card ovascular r sk fac tors cerebrovascular changes Leuko‐ara os s
The mos t prevalen t sub type of VaD s subcortcal schem c VaD S VDDa Hyper tens on causes a d sease
of the small vessels ar ter oscleros sD, wh ch subsequen tly causes an occlus on or hypoperfus ona An
occlus on leads to a comple te nfarcton lacunar s ta teD, and a hypoperfus on w ll lead to an
ncomple te nfarcton wh ch damages the wh te mater B nswanger’s d seaseDa
However, a cl n cal s troke s no t a necessary prerequ s te for develop ng vascular dementaa The
sever ty of the dementa s pos tvely correla ted w th the ncreased a trophy of the h ppocampus and
the cerebrum, more so than w th the wh te mater les onsa h te mater les ons afec t
fron tosubcortcal reg ons severely, espec ally fron tos tr a tal c rcu tsa
2 types of wh te mater: per ven tr cular long d s tance, around ven tr clesD and subcortcal shor t
d s tances, U-shaped pa thwaysDa The types of wh te mater les ons w ll have d feren t cl n cal
ou tcomes n terms of cogn tve functon nga Per ven tr cular ones have a more profound negatve
efec t on cogn ton
Plaques and tangles have been observed n VaD, bu t those w th many vascular les ons tend to have
less plaques and tangles, so t s no t charac ter stc for VaD! Also the chol nerg c defc t, wh ch s
presen t n those w th VaD, s no t as severe n those w th ADa The chol nerg c defc t occurs because
areas of the chol nerg c basal forebra n are pene tra ted by small ar ter es and therefore are vulnerable
to hyper tens ona Paten ts w th VaD fur ther show nfarctons of the BBM and les ons n the wh te
mater and basal gangl a tha t also have a chol nerg c nnervatona Th s may d srup t the
fron tosubcortcal chol nerg c c rcu tsa
The chol nerg c sys tem BBMD actva tes a vasod la tory sys tem, resultng n an ncrease n cerebral
blood flowa Also the o ther way around appears to be true cerebral blood flow nfluences functon ng
of chol nerg c neuronsa A decrease n glucose me tabol sm w ll decl ne cerebral blood flow, and thus
less actvaton of the chol nerg c sys tema n VaD the reduced cerebral blood flow and chol nerg c
sys tem may lead to a var e ty of cogn tve defc tsa
ARAS: neuronal loss n bra n s tem areas s no t as profound as t s n ADa However, chol nerg c sys tem
and prefron tal cor tex are qu te afec ted n VaDa These areas are vulnerable for wh te mater les onsa
Spec fc functonal c rcu ts:
Fron tos tr a tal and fron toh ppocampal c rcu s are mos t vulnerable for subcortcal wh te mater les ons
and focal lacunar infarctsa Lacunar nfarc ts are ofen seen n the s tr a tuma De ter oraton n mo tor
actv ty w ll resul t and those comb ned w th decl ned cogn tve functons appear to con tr bu te to
depress ona
The a trophy of the h ppocampus seen n VaD s no t s trongly rela ted to wh te mater les onsa Th s s
surpr s ng because the h ppocampus s sens tve to a decrease n vascular zatona Explanaton: o ther
cortcal areas have more prom nen t subcortcal connectons tha t are n terrup ted by wh te ma ter
les ons deafferentatonDa H ppocampus has fewer subcortcal connectons and s therefore less
vulnerable to deaferentatona The en torh nal cor tex for example has many subcortcal connectons
and s therefore more vulnerable to deaferentatona Th s vulnerab l ty of en torh nal cor tex w ll pu t
the fron toh ppocampal c rcu t a t r sk, resultng n worse commun caton be tween h ppocampus and
PFCa Th s can expla n the cogn tve problems seen n VaDa People w th years of hyper tens on tha t
notes
Vascular Dementa
Vascular Dementa VaDD s the second mos t prevalen t sub type of dementaa n persons aged 85 or
older, VaD s more common than ADa More men appear to be afec ted by VaD than womena
R sk fac tors: hypo- and hyper tens on, card ovascular d sease, d abe tes, smok ng, age, low educaton
level eaga no t challeng ng yourselfD, lacunar s trokes and wh te mater les onsa
Card ovascular r sk fac tors cerebrovascular changes Leuko‐ara os s
The mos t prevalen t sub type of VaD s subcortcal schem c VaD S VDDa Hyper tens on causes a d sease
of the small vessels ar ter oscleros sD, wh ch subsequen tly causes an occlus on or hypoperfus ona An
occlus on leads to a comple te nfarcton lacunar s ta teD, and a hypoperfus on w ll lead to an
ncomple te nfarcton wh ch damages the wh te mater B nswanger’s d seaseDa
However, a cl n cal s troke s no t a necessary prerequ s te for develop ng vascular dementaa The
sever ty of the dementa s pos tvely correla ted w th the ncreased a trophy of the h ppocampus and
the cerebrum, more so than w th the wh te mater les onsa h te mater les ons afec t
fron tosubcortcal reg ons severely, espec ally fron tos tr a tal c rcu tsa
2 types of wh te mater: per ven tr cular long d s tance, around ven tr clesD and subcortcal shor t
d s tances, U-shaped pa thwaysDa The types of wh te mater les ons w ll have d feren t cl n cal
ou tcomes n terms of cogn tve functon nga Per ven tr cular ones have a more profound negatve
efec t on cogn ton
Plaques and tangles have been observed n VaD, bu t those w th many vascular les ons tend to have
less plaques and tangles, so t s no t charac ter stc for VaD! Also the chol nerg c defc t, wh ch s
presen t n those w th VaD, s no t as severe n those w th ADa The chol nerg c defc t occurs because
areas of the chol nerg c basal forebra n are pene tra ted by small ar ter es and therefore are vulnerable
to hyper tens ona Paten ts w th VaD fur ther show nfarctons of the BBM and les ons n the wh te
mater and basal gangl a tha t also have a chol nerg c nnervatona Th s may d srup t the
fron tosubcortcal chol nerg c c rcu tsa
The chol nerg c sys tem BBMD actva tes a vasod la tory sys tem, resultng n an ncrease n cerebral
blood flowa Also the o ther way around appears to be true cerebral blood flow nfluences functon ng
of chol nerg c neuronsa A decrease n glucose me tabol sm w ll decl ne cerebral blood flow, and thus
less actvaton of the chol nerg c sys tema n VaD the reduced cerebral blood flow and chol nerg c
sys tem may lead to a var e ty of cogn tve defc tsa
ARAS: neuronal loss n bra n s tem areas s no t as profound as t s n ADa However, chol nerg c sys tem
and prefron tal cor tex are qu te afec ted n VaDa These areas are vulnerable for wh te mater les onsa
Spec fc functonal c rcu ts:
Fron tos tr a tal and fron toh ppocampal c rcu s are mos t vulnerable for subcortcal wh te mater les ons
and focal lacunar infarctsa Lacunar nfarc ts are ofen seen n the s tr a tuma De ter oraton n mo tor
actv ty w ll resul t and those comb ned w th decl ned cogn tve functons appear to con tr bu te to
depress ona
The a trophy of the h ppocampus seen n VaD s no t s trongly rela ted to wh te mater les onsa Th s s
surpr s ng because the h ppocampus s sens tve to a decrease n vascular zatona Explanaton: o ther
cortcal areas have more prom nen t subcortcal connectons tha t are n terrup ted by wh te ma ter
les ons deafferentatonDa H ppocampus has fewer subcortcal connectons and s therefore less
vulnerable to deaferentatona The en torh nal cor tex for example has many subcortcal connectons
and s therefore more vulnerable to deaferentatona Th s vulnerab l ty of en torh nal cor tex w ll pu t
the fron toh ppocampal c rcu t a t r sk, resultng n worse commun caton be tween h ppocampus and
PFCa Th s can expla n the cogn tve problems seen n VaDa People w th years of hyper tens on tha t
